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From the * Department of Biomedical Engineering
and the Department of Obstetrics and
Gynecology, Duke University, Durham, North Carolina.
| Correspondence to: Dr Derek H. Owen, Department of Biomedical Engineering, Duke University, Box 90281, Durham, NC 27708 (e-mail: dhowen{at}duke.edu). |
| Received for publication July 6, 2004; accepted for publication February 12, 2005. |
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Abstract |
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Key words: Composition, human, semen, simulant, microbicide
One component of such research is the in vitro testing of formulations with fluids representative of those that will be encountered within the vagina. Our laboratory has been developing and applying in vitro assays that focus on how the deployment and delivery of contraceptive and prophylactic compounds are affected by the properties of the delivery vehicle and its interactions with the surrounding fluids. To develop these assays using standardized materials of sufficient volume, we have found it useful to employ simulants of ambient biological fluids. Our formulation of a vaginal fluid simulant has been described in a previous publication (Owen and Katz, 1999b), and our semen simulant (and earlier versions) was presented in a number of studies of contraceptive and microbicidal gels (Owen et al, 2003, 2004; Geonnotti and Katz, 2004; Geonnotti et al, 2005a; Geonnotti et al, 2005b). Here we describe the formulation of a semen simulant embodying salient physical and chemical components and properties of human semen. This is based on a comprehensive review of the literature, and we present here, as well, an updated summary of the constituents of human semen.
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Materials and Methods |
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Human semen is a mixture of components produced by several different glands. These components are incompletely mixed during ejaculation and, hence, the initial ejaculate is not an entirely homogeneous mixture. The first portion of the ejaculate, about 5% of it, is made up of secretions from the Cowper (bulbourethral) and Littre glands. The second portion derives from the prostate and contributes from 15% to 30% to the ejaculate. There follow small contributions of the ampulla and epididymis and, finally, of the seminal vesicles, which contribute the remainder, and majority, of the ejaculate (Polakoski et al, 1976; Mann and Lutwak-Mann, 1981; Coffey, 1995).
The secretions of the organs contributing to the ejaculate differ in composition, and there has been a longstanding interest in evaluating the composition of semen from a diagnostic point of view (Eliasson, 1982). The prostate is the main source of the acid phosphatase, citric acid, inositol, calcium, zinc, and magnesium found in the ejaculate. The seminal vesicles' contribution is rich in fructose, ascorbic acid, and prostaglandins, while the concentrations of L-carnitine and neutral alpha-glucosidase are indications of epididymal function (WHO Manual, 1999). A small portion of the fructose present originates from ampulla of the ductus deferens.
The data used in formulating our simulant derive from a large number of articles describing the composition of semen and seminal plasma. The choice of composition, pH, viscosity, and buffering capacity of our simulant was complicated by a number of factors that made direct comparisons between studies difficult. The most important difference across the studies was in the choice of donors used. Many studies were performed on patients attending infertility clinics or on patients who were being screened for a variety of pathological conditions. In our work, studies in which the donors were demonstrably infertile or pathological were excluded. Included were studies in which donors were normozoospermic patients at infertility clinics or in which donors were fertile controls in studies involving semen. The number of donors used in each study varied; however, in our study, the data are not weighted by sample size, since in comparing studies, particularly those that used different measurement techniques, a larger sample size does not necessarily imply greater accuracy.
Some studies were performed on whole semen and others on seminal plasma alone. Sperm make up only a small portion of the whole semen, from 1% to 5% of the total volume (Mortimer, 1994). Most studies of the composition of both seminal plasma and whole semen indicate that the presence of sperm does not significantly influence the results; for instance, they make little contribution to the total ionic content of the semen (Bondani et al, 1973). In reviewing previous studies, it was sometimes difficult to determine if whole semen or plasma was used. Whole semen is assumed unless some separation procedure is described. Except where noted, composition data for whole semen and seminal plasma are considered together.
Another factor influencing the results of the various studies reviewed was the method of sample collection and preparation. The most important variable here was usually the length of time since ejaculation. Time after collection is particularly important for pH measurements, since the pH changes as a result of increased CO2 concentration and lactic acid production. The rheological properties of the semen sample also change with time, as the material first coagulates and then liquefies. This process is accompanied by biochemical changes in composition. If sperm are present in the sample, over time they may influence the measured composition, as a result of binding of plasma components to the sperm and to sperm metabolic activity. Sperm metabolic activity can alter composition due to fructolysis, glycolysis, and the excretion of metabolic wastes. In addition, after ejaculation, some of the sperm cell contents may leak out into the surrounding plasma (Mann and Lutwak-Mann, 1981). Other postejaculatory concerns include proteolysis and the rise of free choline accompanied by the crystallization of insoluble spermine phosphate (Mann and Lutwak-Mann, 1981). Results can even be influenced by the type of sample container used. Studies have shown that high-quality polypropylene is the best material (Balerna et al, 1985) and that glass can contain enough zinc to influence zinc concentration measurements (Colleen et al, 1975).
A few of the articles reviewed measured composition on a per-ejaculate basis, and from a diagnostic point of view, per-ejaculate results may be more useful (Grizard et al, 1985). The overwhelming majority of the articles reviewed, however, measured composition on a per-volume basis, and this is the basis used throughout our study. When possible, per-ejaculate data were used here after conversion to a per-volume measurement.
The techniques used to measure particular semen components or properties sometimes differed from study to study. These different methods will be discussed below as each component and property is reviewed. A detailed description of the various assays used to measure semen composition and properties can be found in Mortimer (1994). Almost all of the property measurements used in this study were performed on semen obtained by masturbation. For interesting comparisons of semen composition measured on samples collected by masturbation vs coitus, see Hotchkiss et al (1938) and Purvis et al (1986).
The semen simulant proposed in this article is intended to model the properties of semen produced by healthy male donors after complete liquefaction of the semen. The proposed semen simulant is designed to incorporate information about chemical composition determined by previous researchers, with an emphasis on modeling the pH and buffering capacity, ions, osmolarity, sugars and protein composition, and viscosity of the material. We now consider each of these in turn.
pH and Buffering Capacity
Semen has a very high buffering capacity, much higher than that of most
other fluids in the body. Semen maintains its pH near neutral in the acidic
vaginal environment, providing the sperm with the opportunity to enter the
neutral pH cervical mucus. The pH of human semen is a matter of some debate
(Meacham, 2002); there is
considerable variation in the pH measurements reported by different
researchers. Most researchers have used one of two techniques for measuring
semen acidity—pH indicator paper/colorimetry or a pH electrode (in
almost all cases, whole semen was used). One study comparing the two methods
found slightly higher values when pH paper was used
(Haugen and Grotmol, 1998). The measured pH can depend on the length of time since ejaculation, and it
tends to increase shortly after ejaculation as a result of loss of
CO2 (Makler et al,
1981; Wolters-Everhardt et
al, 1986). Further aging of whole semen can result in a
substantial decrease in pH resulting from fructolysis and the production of
lactic acid (Shedlovsky et al,
1942; Searcy and Simms,
1967).
The high buffering capacity of semen has been reported in a number of studies, each of which presents its results in a different way. Tynen (1939) reported that the pH of 1 mL of semen can be reduced to 6.0 by the addition of 5.5 mL of 0.01 N HCl. A study conducted by Shedlovsky et al (1942) reported results as a curve of measured pH vs the volume of 0.50 N HCl solution added. A similar study (Mandal and Bhattacharyya, 1987b) measured buffering capacity as the change of pH resulting from adding 0.4 mL of 0.1 N HCl to 0.3 mL of seminal plasma. In a study of infertile men, Wolters-Everhardt et al (1986) measured a buffering capacity of 41.1 slyke. A slyke is the number of micromoles of HCl added to 1 mL of test solution to get a 7 to 6 pH change. It is somewhat difficult to directly compare these results. However, expressed as micromoles of H+ per milliliter of semen required for a 1 pH unit change, they are approximately: Tynen, 25; Shedlovsky, 20; Mandal and Bhattacharyya, 15; and Wolter-Everhardt et al, 40.
There is some debate as to the source of the high buffering capacity of semen. Searcy and Simms (1967) proposed that citrate is an important source of seminal buffering capacity. A study by Wolters-Everhardt et al (1987) of the contribution of HCO3/CO2 to buffering capacity concluded that HCO3/CO2 contributes 24.9%, protein contributes 28.5%, and that the other half is due to low–molecular weight components such as citrate, inorganic phosphate, and pyruvate. After considering the results of the studies discussed above, we formulated our semen simulant from a phosphate buffer solution (containing citrate and protein) to have a target pH of 7.7 and a target buffering capacity of 25 slyke. A summary of the studies considered of semen pH and their results is given in Table 1.
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Citrate
Citrate is one of the most important anions present in human semen.
Although citrate has high affinity for calcium, magnesium, and zinc, the
citrate concentration is more than double the divalent metal concentration;
consequently, much of the seminal citrate is strongly anionically charged
(Arver, 1982a;
Arver and Sjoberg, 1982; Kavanagh, 1985). Semen may owe
its high calcium ion buffering capacity to citrate, and citrate is probably
the major regulator of ionized calcium levels in seminal plasma
(Fong et al, 1986;
Magnus et al, 1990). Most
studies measuring citric acid concentration used either enzymatic or
spectrophotometric techniques. Our simulant is formulated to have a target
citrate concentration of 528 mg/100 mL. The studies used are summarized in
Table 2.
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Ions
The measurement of calcium concentration in semen is of great interest as a
result of its relation to sperm motility, metabolism, the acrosome reaction,
and fertilization itself (Sorensen et al,
1999). Only a small portion, 2%–4%, of the calcium in semen
is present in ionized form (2%, Arver,
1982b; 4%, Ponchietti et al,
1984). Measurement of calcium concentration can be complicated,
since exposure to air results in a temperature-dependent decrease in ionized
calcium levels (Arver and Sjoberg,
1983). In addition, binding with other compounds (citrate,
phosphate, proteins, etc) may reduce calcium activity (ionization); semen has
a very high calcium buffering capacity (see Citrate above)
(Mann and Lutwak-Mann, 1981;
Arver and Sjoberg, 1982;
Ford and Harrison, 1984; Fong et al, 1986;
Magnus et al, 1990). Calcium
also binds to the sperm surface, which can lead to differences between
measurements on whole semen vs seminal plasma
(Mann and Lutwak-Mann,
1981).
The other important ions found in human semen are magnesium, potassium, sodium, and zinc. The concentrations of calcium, magnesium, and zinc are highly correlated (Homonnai et al, 1978; Adamopoulos and Deliyiannis, 1983). Studies measuring salt concentrations in semen indicate substantial variation among donors (Girgis et al, 1980). Measurements of magnesium, potassium, sodium, and zinc concentrations are complicated by the tendency of those elements to form complexes with other components of the semen. Magnesium and zinc are also found complexed with other molecules, which can sometimes be bound to the surface of the sperm cells (Lindholmer and Eliasson, 1974; Mann and Lutwak-Mann, 1981; Hirsch et al, 1991). Zinc is excreted from the prostate as a low–molecular weight complex with citrate. After ejaculation, 50% is redistributed and bound to medium– and high–molecular weight compounds from the seminal vesicles (Lindholmer and Eliasson, 1974; Arver and Eliasson, 1982; Mandal and Bhattacharyya, 1990). Citrate is probably the main low–molecular weight zinc ligand (Arver, 1982a).
One study, Quinn et al (1965), examined the differences in salt concentrations measured in whole semen vs plasma. It found a higher concentration of calcium and magnesium in plasma vs whole semen; for sodium, the concentration in whole semen was greater than in plasma. Measurements of salt concentrations in the studies reviewed were usually conducted using atomic absorption spectrophotometry, flame photometry, or ion-selective electrode analyzers. Our simulant is formulated to have target calcium, chloride, magnesium, potassium, sodium, and zinc concentrations of 27.6, 142, 11.0, 109, 300, and 16.5 mg/100 mL, respectively, (see Table 3).
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Osmolarity
Semen is notable for its high osmolarity, which is substantially higher
than that of blood plasma. The osmolarity of semen depends greatly on the
concentration of sugars and other organics concentrations as well as ionic
salt concentrations (Mandal and
Bhattacharyya, 1987b). Some researchers have noted that osmolarity
increases measurably with semen aging
(Velazquez et al, 1977).
After a review of the relevant literature, we formulated our semen simulant to
have a target osmolarity of 354 mosmolar. A summary of the studies considered
and their results is given in Table
4.
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Fructose and Glucose
Fructose concentration, because it is considered a measure of seminal
vesicle function, has been studied in great detail. Studies indicate that
there is a wide variation in fructose concentration
(Nun et al, 1972), and this
concentration can be a function of a number of factors, including time since
collection and the age of the donor (Mauss
et al, 1974; Kothari et al,
1977). Fructose is an important source of energy for the sperm,
and, hence, measurements of fructose concentration in whole semen can change
over time as a result of fructolysis, the primary source of lactic acid in
semen (King and Mann, 1959;
Mann and Lutwak-Mann, 1981).
Fructose is also likely involved in protein complexes, particularly in
coagulated semen (Montagnon et al,
1982). Glucose may also be an important source of energy to
spermatozoa (Peterson and Freund,
1971; Martikainen et al,
1980) and is present in substantial concentrations.
Most of the studies reviewed measured fructose concentration using the resorcinol method. Sheth and Rao (1959) showed that the resorcinol method is not accurate and that the chromatographic method should be used. The chromatographic method measures only fructose, while other methods can measure other reducing substances as well. Sheth and Rao also showed that the concentration of reducing substances increases in semen with time and that this can confound fructose measurements made using the resorcinol method.
One group of researchers has proposed that absolute fructose concentration is not the best method for measuring seminal vesicle function and has further proposed a "corrected fructose" value, which is the fructose concentration (mg/mL) multiplied by the log of the sperm count (mil/mL) (Gonzales et al, 1988, 1993). Gonzales et al showed that this corrected fructose value correlates well with measures of seminal vesicle dysfunction. This derived measure has not been universally accepted.
The mean average fructose and glucose concentrations in the studies we reviewed were 272 mg/100 mL and 102 mg/100 mL, respectively. We have used these concentrations in our simulant, but it should be noted that the variation in the measured values among studies is very large (range of 136–628 mg/100 mL for fructose, range of 4–300 mg/100 mL for glucose). These studies are summarized in Table 5.
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Protein
The bulk of the proteins found in semen derive from the seminal vesicles,
although albumin is mainly of prostatic origin
(Hirsch et al, 1991). A review
of the literature indicates that albumin makes up about one third of the
protein content of semen. The amino acid content of semen is much higher than
that of plasma, and it increases rapidly (particularly glutamic acid) in the
hours following ejaculation (Keil et al,
1979; Frohlich et al,
1980).
Protein concentration is difficult to accurately measure and depends greatly on the measurement technique employed. Hernvann et al (1987) showed that measurements made using the Biuret reaction and Lowry's methods produce much higher values than do Meulemans' method. Spectrophotometric methods produce even lower values and are only useful for measuring relative rather than absolute protein concentrations (Polak and Daunter, 1989).
In the studies reviewed, the average albumin concentration was 1550 mg/100 mL, and the average total protein concentration was 5040 mg/100 mL. We formulated our simulant with a protein content of 5040 mg/100 mL, with the entire protein contribution made up of bovine serum albumin (see Table 6).
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Viscosity
The rheological properties of semen change dramatically after ejaculation;
the initial ejaculate quickly coagulates into a gelatinous material, and this
material then liquefies. Liquefaction occurs over a period of 5 minutes in
vivo, but may take 20–30 minutes in vitro
(Montagnon et al, 1982;
Polak and Daunter, 1989). The
biochemical mechanisms of this coagulation and liquefaction have been
investigated by numerous researchers (eg,
Mandal and Bhattacharyya,
1985; Polak and Daunter,
1989); the coagulation factors derive from the seminal vesicles,
while liquefying factors come from the prostate
(Gonzales et al, 1993).
Given the biological importance of this process, it is surprising how little quantitative data there are on the physical properties of semen. A measurement of "viscosity" is frequently performed as recommended in the WHO Manual (1999), which defines an abnormal viscosity sample as one that can be drawn out to more than 2 cm with a rod or pipette. This procedure is not a true measurement of viscosity, but rather a measure of the combined elastic and viscous properties of the material. However, it is still used frequently to separate semen samples into normal vs high-viscosity or "high-consistency" samples (eg, Dube et al, 1989; Carpino and Siciliano, 1998). More rigorous measurement methods usually involve comparison of the viscosity of semen to that of water using a capillary tube viscometer. This method is useful in comparing samples, but it provides little quantitative information about the rheological properties of the material, as it ignores elasticity, thixotropy, shear thinning, yield stresses, and other important non-Newtonian properties.
The studies comparing the viscosity of semen to that of water are summarized as follows. Tjioe and Oentoeng (1968), using a Hellige viscometer (a 2-capillary system), measured an average viscosity of whole semen of 3.92 centipoise (cP), with a wide range of values (1.3–23.3 cP). Note that the viscosity of water at 25°C/37°C is 0.8904/0.6915 cP. Ray et al (1977) measured the viscosity of previously frozen semen using a capillary device and determined that semen specimens from normal, azoospermic, and vasectomized patients tended to have the same viscosity, while the viscosity of oligospermic patients was higher. We can infer from their results a viscosity of about 3.2 cP for normal whole semen at 37°C. Nag et al (1979) used a U-tube capillary viscometer to study the viscosity of seminal plasma and whole semen from normal, azoospermic, and vasectomized patients. They concluded that only about a third of the differences in viscosity were due to sperm, with most of the remainder due to differences in plasma content. We can infer from their results a viscosity for normal semen of about 3.1 cP at 37°C. Another similar study comparing capillary flow of semen to water was conducted by Moulik et al (1989). They did not report any quantitative information but noted that high viscosity can be an indication of antibodies in the plasma and/or genital tract infection.
The most complete rheological characterization of semen (although only one donor was studied) was performed by Dunn and Picologlou (1977a,b). The material was shown to behave as a viscoelastic material shortly following ejaculation. After full liquefaction it behaved as a Newtonian fluid with a viscosity of 3.37 cP at 33.2°C. These researchers tracked the time course of liquefaction by measuring viscoelastic properties and found that at ejaculation, following coagulation, the material has a viscosity about 100 times its final value. Hubner et al (1985) used a concentric cylinder viscometer to measure the viscosity of previously frozen semen samples at 3 different shear rates. They measured a viscosity of 6.71, 6.11, and 5.77 cP (23°C) at shear rates of 45, 90, and 135 seconds-1, respectively. They concluded that there is no correlation between viscosity and sperm motility and that viscosity was only influenced by sperm count when the count was very high. A study by Lin et al (1992), conducted using a rotational cone and plate viscometer, found a viscosity of 6.84 cP for normospermic semen, although no shear rate was given for this measurement. Gonzalez-Estrella et al (1994), using a Brookfield viscometer, demonstrated that 90 minutes following ejaculation, viscosities in 2 separate studies of normal consistency samples (as determined by the WHO standard) were 7.4 and 7.7 cP at 25°C. The shear rates experienced by the semen in the capillary viscometers described above are much higher than in the rotational viscometers, and so the difference in the results between these two types of instruments (viscosities of 3–4 at high shear rate vs 6–7 at low shear rate) can be explained by the shear thinning nature of the fluid.
Volume
The volume of a human ejaculate has been extensively studied. In almost all
the studies we reviewed, the researchers measured volumes following
masturbation. One study found that volumes were significantly higher, 4.99 mL
vs 3.92 mL, when collection occurred during coitus
(Purvis et al, 1986), while
another study by Hotchkiss et al
(1938) found a difference in
the other direction (3.0 mL by withdrawal, 2.3 mL by condom). Our review of
over 30 articles in the literature concluded that the average volume is 3.4
mL, and this is the volume of our simulant referenced in our studies of
vaginal gel formulations. These results are summarized in
Table 7.
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Other Semen Components
Two other components have been included in our simulant, lactic acid at 62
mg/100 mL (Goldblatt, 1935;
MacLeod and Hotchkiss, 1942; Lundquist, 1949) and urea at
45 mg/100 mL (Goldblatt, 1935; Srivastava et al, 1984;
Hirsch et al, 1991). Materials
that are found in small quantities, such as trace elements, have been excluded
from our simulant as biophysically, if not biochemically, unimportant. Several
components present in substantial quantities have also been excluded for
reasons of simplicity and practicality. These include lipids, usually present
as "lipid bodies" (Mann,
1964), choline, sialic acid, inositol, and spermine, pyruvate,
creatine, and ascorbic acid.
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Simulant Formulation |
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First we mixed the following: 5.46 mL of 0.123 M sodium phosphate monobasic, monohydrate with 49.14 mL of 0.123 M sodium phosphate dibasic, anhydrate. Next, we added the following: sodium citrate dehydrate (813 mg); potassium chloride (90.8 mg); potassium hydroxide (88.1 mg); fructose (272 mg); glucose, anhydrous (102 mg); lactic acid (62 mg); urea (45 mg); and bovine serum albumin (5.04 g). Separately we mixed the following: 101 mg of calcium chloride dihydrate in 15.13 mL of water; 92 mg of magnesium chloride hexahydrate in 15.13 mL of water; and 34.4 mg of zinc chloride in 15.13 mL of water. We slowly added first the calcium solution, then the magnesium solution, and finally the zinc solution to the phosphate buffer solution. We raised the pH with sodium hydroxide to 7.7, sterile filtered the formulation, and froze it until ready for use.
This recipe results in a semen simulant with the following properties, as compared to those measured for human semen. Measured values are mean average values from literature: ph: semen, 7.7; simulant, 7.7; citrate (mg/100 mL): semen, 528; simulant, 523; chloride (mg/100 mL): semen, 142; simulant, 142; calcium (mg/100 mL): semen, 27.6; simulant, 27.6; magnesium (mg/100 mL): semen, 11.0; simulant; 11.0; potassium (mg/100 mL): semen, 109; simulant, 109; sodium (mg/100 mL): semen, 300; simulant, 484; zinc (mg/100 mL): semen, 16.5; simulant, 16.5; osmolarity (mosm): semen, 354; simulant, 340; fructose (mg/100 mL): semen, 272; simulant, 272; glucose (mg/100 mL): semen, 102; simulant, 102; protein (g/100 mL): semen, 5.04; simulant, 5.04; lactic acid (g/100 mL): semen, 62; simulant, 62; urea (g/100 mL): semen, 45; simulant, 45; buffering capacity (slyke): semen, 25; simulant, 38; and viscosity (cP): semen, 3–7; simulant, see following.
Our semen simulant, as formulated above, has a viscosity of about 1.3 cP. The viscosity of the simulant can be elevated to 4 cP by the addition of 0.17% methyl cellulose. Methyl cellulose was chosen because the properties of its aqueous solutions have been shown to be relatively insensitive to changes in pH and ionic strength (Rossi et al, 1995; Ghannam and Esmail, 1997) and have been demonstrated to be viable media in human sperm penetration studies (Ivic et al, 2002).
There is a long history of interest, both clinical and biological, in the composition of human semen. Many reviews have been published, including the classic books by Mann (1964) and Mann and Lutwak-Mann (1981). Taken as a review article, the present article contributes to our understanding of the physical and chemical properties of semen from normal men. However, the motivation for our work derives primarily from the need to create a standardized simulant fluid for human semen for use in research studies related to drug delivery to the human vagina. As noted in the introduction to this article, drug delivery formulations (for therapeutic, contraceptive, and prophylactic applications) may encounter semen during their residence within the vagina, and the resulting interactions can affect biological functionality of the formulations. The rational development of efficacious vaginal formulations requires standardized use of fluids that embody salient properties of ambient fluids within the human vagina. This semen simulant was developed to have the same physical and chemical properties known to influence intravaginal drug delivery gel efficacy and has proven useful in research into contraceptive and prophylactic drug delivery. We should note that this medium was not developed as a culture medium for spermatozoa or other microorganisms; it could, however, be adapted for such purposes.
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Acknowledgments |
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Footnotes |
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References |
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Adamopoulos DA, Deliyiannis V. Seminal plasma magnesium, calcium and inorganic phosphate concentration in normozoospermic and subfertile men. Andrologia. 1983; 15: 648 -654.[Medline]
Arver S. Zinc and zinc ligands in human seminal plasma. III. The principle low molecular weight zinc ligand in prostatic secretion and seminal plasma. Acta Physiol Scand. 1982a; 116: 67 -73.[Medline]
Arver S. Studies on zinc and calcium in human seminal plasma. Acta Physiol Scand. 1982b; 507(suppl): 1 -17.
Arver S, Eliasson R. Zinc and zinc ligands in human seminal plasma, II. Contribution by ligands of different origin to the zinc binding properties of human seminal plasma. Acta Physiol Scand. 1982; 115: 217 -224.[Medline]
Arver S, Sjoberg HE. Calcium fractions in seminal plasma and functional properties of human spermatozoa. Acta Physiol Scand. 1982;116: 159 -165.[Medline]
Arver S, Sjoberg HE. Ionized calcium in human seminal plasma. Scand J Clin Lab Invest. 1983; 43(suppl): 123 -126.[Medline]
Baker JR. The examination of semen specimens. J Contraception. 1939;4: 127 -129.
Balerna M, Nutini L, Eppenberger U, Campana A. Technology and instrumentation for semen analyses and AIH/AID. Effect of plastic and glass on sperm motility, pH, and oxidation. Arch Androl. 1985; 15: 225 -230.[Medline]
Bhushan S, Pandey RC, Singh SP, Pandey DN, Seth P. Some observations on human semen analysis. Indian J Physiol Pharmacol. 1978;22: 393 -396.[Medline]
Biswas S, Ferguson KM, Stedronska J, Baffoe G, Mansfield MD, Kosbab MH. Fructose and hormone levels in semen: their correlations with sperm counts and motility. Fertil Steril. 1978; 30: 200 -204.[Medline]
Bondani A, Aspeitia E, Aznar R, Gomez-Arzapalo E, Pascual C, Giner J. Correlation between sperm motility and electrolyte composition of seminal fluid in normal and infertile men. Fertil Steril. 1973; 24: 150 -154.[Medline]
Carpino A, Siciliano L. Unaltered protein pattern/genital tract secretion marker levels in seminal plasma of highly viscous human ejaculates. Arch Androl. 1998; 41: 31 -35.[Medline]
Chaudhari AR, Singh R, Bhat KS, Ingley KN. pH of semen in normal and abnormal ejaculates. Indian J Physiol Pharmacol. 1990; 34: 285 -286.[Medline]
Coffey D. What is the prostate and what is its function? In: Robaire B, Pryor JL, Trasler JM, eds. Handbook of Andrology. Lawrence, Kans: Allen Press Inc; 1995: 21 -24.
Colleen S, Mardh PA, Schytz A. Magnesium and zinc in seminal fluid of healthy males and patients with non-acute prostatitis with and without gonorrhoea. Scand J Urol Nephrol. 1975; 9: 192 -197.[Medline]
Cooper TG, Jockenhovel F, Nieschlag E. Variations in semen
parameters from fathers. Hum Reprod. 1991; 6: 859
-866.
Davis E, McCune WW. Fructolysis of human spermatozoa. Fertil Steril. 1950; 1: 362 -372.[Medline]
Dondero F, Sciarra F, Isidori A. Evaluation of relationship between plasma testosterone and human seminal citric acid. Fertil Steril. 1972;23: 168 -171.[Medline]
Dube JY, Gaudreault D, Tremblay RR. The concentration of immunoreactive prostate specific antigen is not decreased in viscous semen samples. Andrologia. 1989; 21: 136 -139.[Medline]
Dunn PF, Picologlou BF. Investigation of the rheological properties of human semen. Biorheology. 1977a; 14: 277 -292.[Medline]
Dunn PF, Picologlou BF. Variation in human semen viscoelastic properties with respect to time post ejaculation and frequency of ejaculation. Int J Fertil. 1977b; 22: 217 -224.[Medline]
Eliasson R. Biochemical analysis of human semen. Int J Androl. 1982;5(suppl): 109 -119.
Falk HC, Kaufman SA. What constitutes a normal semen? Fertil Steril. 1950; 1: 489 -503.[Medline]
Fong JC, Lin CH, Wei YH, Ho LT, Hong CY. Calcium buffering capacity of human seminal plasma: the role of EGTA in stimulating sperm motility. Chin J Physiol. 1986; 29: 7 -12.[Medline]
Ford WCL, Harrison A. The role of citrate in determining the activity of calcium ions in human semen. Int J Androl. 1984; 7: 198 -202.[Medline]
Frohlich JU, Nissen HP, Heinze I, Schirren C, Kreysel HW. Free aminoacid composition of human seminal plasma in different andrological diagnoses. Andrologia. 1980; 12: 162 -166.[Medline]
Geonnotti AR, Katz DF. Erosion of surface coating of microbicides formulations due to shearing and contact with vaginal fluids. London, United Kingdom: Microbicides Meeting; 2004 .
Geonnotti AR, Kieweg SL, Katz DF. Distribution and erosion of microbicides formulation coating: mechanistic analysis. Washington, DC: Alliance for Microbicide Development Meeting; 2005a. In press.
Geonnotti AR, Peters JJ, Katz DF. Erosion of microbicide formulation coating layers: effect of contact and shearing with vaginal fluid or semen. J Pharm Sci. 2005b. In press.
Gershbein LL, Thielen DR. Enzymatic and electrolytic profiles of human semen. Prostate. 1988; 12: 263 -269.[Medline]
Ghannam MT, Esmail MN. Rheological properties of carboxymethyl cellulose. J Appl Polym Sci. 1997; 64: 289 -301.[CrossRef]
Girgis SM, Hafiez AA, Mittawy B, Hamza KH. Electrolyte concentration in semen. Andrologia. 1980; 12: 323 -327.[Medline]
Goldblatt MW. Constituents of human seminal plasma. Biochem J. 1935; 29: 1346 -1357.
Gonzales GF. Corrected seminal fructose test. Arch Androl. 1994;33: 17 -22.[Medline]
Gonzales GF, Garcia-Hjarles M, Napuri R. Corrected seminal fructose levels: index of secretory activity of seminal vesicles. Arch Androl. 1988;21: 135 -142.[Medline]
Gonzales GF, Kortebani G, Mazzolli AB. Hyperviscosity and hypofunction of the seminal vesicles. Arch Androl. 1993; 30: 63 -68.[Medline]
Gonzales GF, Sanchez A. High sperm chromatin stability in semen with high viscosity. Arch Androl. 1994; 32: 31 -35.[Medline]
Gonzalez-Estrella JA, Coney P, Ostash K, Karabinus D. Dithiothreitol effects on the viscosity and quality of human semen. Fertil Steril. 1994; 62: 1238 -1243.[Medline]
Gopalkrishman K, Hinduja IN, Kumar TC. Determining the osmolality of seminal fluid aids in the rapid diagnosis of the fertilizing potential of spermatozoa. J In Vitro Fertil Embryo Transf. 1989; 6: 119 -121.[CrossRef][Medline]
Gregoire AT, Moran MJ. The enzyme activity, protein and fructose content of normal, oligospermic, postvasectomy, and infertile azoospermic men. Fertil Steril. 1973; 24: 208 -211.[Medline]
Grizard F, Janny L, Hermabessiere J, Sirot J, Boucher D. Seminal biochemistry and sperm characteristics in infertile men with bacteria in ejaculate. Arch Androl. 1985; 15: 181 -186.[Medline]
Harvey C. Fructose and citric acid in human semen. Proc Soc Stud Fertil. 1951;3: 56 -68.
Haugen TB, Grotmol T. pH of human semen. Int J Androl. 1998;21: 105 -108.[CrossRef][Medline]
Hernvann A, Gonzales J, Diemert MC, Galli J. Determination of total protein in human seminal plasma. Andrologia. 1987; 19: 233 -237.
Hirsch IH, Jeyendran RS, Sedor J, Rosecrans RR, Staas WE. Biochemical analysis of electroejaculates in spinal cord injured men: comparison to normal ejaculates. J Urol. 1991; 145: 73 -76.[Medline]
Homonnai ZT, Matzkin H, Fainman N, Paz G, Kraicer PF. The cation composition of the seminal plasma and prostatic fluid and its correlation to semen quality. Fertil Steril. 1978; 29: 539 -542.[Medline]
Homonnai ZT, Paz G, Weiss JN, David MP. Quality of semen obtained from 627 fertile men. Int J Androl. 1980; 3: 217 -228.[Medline]
Hotchkiss RS, Brunner EK, Grenley P. Semen analyses of two hundred fertile men. Am J Med Sci. 1938; 196: 362 -384.
Hubner HM, Heidl R, Krause W. Investigation of flow behaviour (viscosity) from human seminal fluid with a rotational viscometer. Andrologia. 1985; 17: 592 -597.[Medline]
Huggins CB, Johnson AA. Chemical observations on fluids of the
seminal tract: I. Inorganic phosphorus, calcium, non-protein nitrogen and
glucose content of semen and of seminal vesicle, prostate and spermatocele
fluids in man. Am J Physiol. 1933; 103: 574
-581.
Huggins C, Scott WW, Heinen JH. Chemical composition of human semen
and of the secretions of the prostate and seminal vesicles. Am J
Physiol. 1942;136: 467
-473.
Ivic A, Onyeaka H, Girling A, Brewis IA, Ola B, Hammadieh N,
Papaioannou S, Barratt CLR. Critical evaluation of methylcellulose as an
alternative medium in sperm migration tests. Hum
Reprod. 2002;17: 143
-149.
Jathar VS, Hirwe R, Desai S, Satoskar RS. Seminal fructose, citric acid and phosphatase levels and their relation to the sperm count in man. Indian J Physiol Pharmacol. 1977; 21: 186 -190.[Medline]
Jeyendran RS, Van der Ven HH, Rosecrans R, Perez-Pelaez M, Al-Hasani S, Zaneveld LJD. Chemical constituents of human seminal plasma: relationship to fertility. Andrologia. 1989; 21: 423 -428.[Medline]
Katz DF, Henderson MH, Owen DH, Plenys AM, Walmer DK. What is needed to advance vaginal formulation technology? In: Rencher WF, ed. Proceedings of the 5th Contraceptive Research and Development Program Workshop. Philadelphia, Pa: Lippencott-Raven; 1998 : 90-99.
Kavanagh JP. Sodium, potassium, calcium, magnesium, zinc, citrate and chloride content of human prostatic and seminal fluid. J Reprod Fertil. 1985;75: 35 -41.
Keil M, Wetterauer U, Heite HJ. Glutamic acid concentration in human semen—its origin and significance. Andrologia. 1979; 11: 385 -391.[Medline]
Kilic S, Sarica K, Yaman O, Soygur T, Gogus O, Yaman LS. Effect of total and ionized calcium levels of seminal fluid on sperm motility. Urol Int. 1996;56: 215 -218.[CrossRef][Medline]
King TE, Mann T. Sorbitol metabolism in spermatozoa.
Proc R Soc Lond B Biol Sci. 1959; 151: 226
-243.
Kothari LK, Gupta AS, Chaturvedi KC, Paliwal OL. Seminal fructose and acid phosphatase in vasectomised men. Int J Fertil. 1977;22: 60 -62.[Medline]
Landau RL, Loughhead R. Seminal fructose concentration as an index of androgenic activity in man. J Clin Endocrinol Metab. 1951;11: 1411 -1424.
Lewin LM, Beer R, Lunenfeld B. Epididymis and seminal vesicle as sources of carnitine in human seminal fluid: the clinical significance of the carnitine concentration in human seminal fluid. Fertil Steril. 1976;27: 9 -13.[Medline]
Lewis-Jones DI, Aird IA, Biljan MM, Kingsland CR. Effects of sperm
activity on zinc and fructose concentrations in seminal plasma. Hum
Reprod. 1996;11: 2465
-2467.
Lin MC, Tsai TC, Yang YS. Measurement of viscosity of human semen with a rotational viscometer. J Formos Med Assoc. 1992; 91: 419 -423.[Medline]
Lindholmer C. Survival of human spermatozoa in different fractions of split ejaculate. Fertil Steril. 1973; 24: 521 -526.[Medline]
Lindholmer C, Eliasson R. Zinc and magnesium in human spermatozoa from different fractions of split ejaculates. Int J Fertil. 1974;19: 45 -48.[Medline]
Lundquist F. Aspects of the biochemistry of human semen. Acta Physiol Scand Supp 66. 1949; 19: 1 -105.
MacLeod J. The male factor in fertility and infertility: an analysis of ejaculate volume in 800 fertile men and in 600 men in infertile marriage. Fertil Steril. 1950; 1: 347 -361.[Medline]
MacLeod J, Freund M. Influence of spermatozoal concentration and
initial fructose level on fructolysis in human semen. J Appl
Physiol. 1958;13: 501
-505.
MacLeod J, Heim LM. Characteristics and variations in semen specimens in 100 normal young men. J Urol. 1945; 54: 474 -482.[Medline]
MacLeod J, Hotchkiss RS. The distribution of spermatozoa and of certain chemical constituents in the human ejaculate. J Urol. 1942;48: 225 -229.
Magnus O, Abyholm T, Kofstad J, Purvis K. Ionized calcium in human
male and female reproductive fluids: relationships to sperm motility.
Hum Reprod. 1990; 5: 94
-98.
Makler A, David R, Blumenfeld Z, Better OS. Factors affecting sperm motility. VII. Sperm viability as affected by change of pH and osmolarity of semen and urine specimens. Fertil Steril. 1981; 36: 507 -511.[Medline]
Mandal A, Bhattacharyya AK. Physical properties and non-enzymatic components of human ejaculates. Relationship to spontaneous liquefaction. Int J Androl. 1985; 8: 224 -231.[Medline]
Mandal A, Bhattacharyya AK. Grouping of human ejaculates according to the degree of coagulation and the relationship to the levels of choline and cholinesterase. Int J Androl. 1986; 9: 407 -415.[Medline]
Mandal A, Bhattacharyya AK. Phosphate, zinc, calcium, citric acid, and acid phosphatase in human ejaculates as related to coagulation/liquefaction. Arch Androl. 1987a; 19: 275 -283.[Medline]
Mandal A, Bhattacharyya AK. Differences in osmolality, pH, buffering capacity, superoxide dismutase and maintenance of sperm motility in human ejaculates according to the degree of coagulation. Int J Androl. 1987b;11: 45 -51.
Mandal A, Bhattacharyya AK. Biochemical composition of washed human seminal coagulum in comparison to sperm-free semen from the same donors. J Reprod Fertil. 1990; 88: 113 -118.
Mann T. The Biochemistry of Semen and of the Male Reproductive Tract. New York, NY: John Wiley and Sons Inc; 1964 .
Mann T, Lutwak-Mann C. Male Reproductive Function and Semen: Themes and Trends in Physiology, Biochemistry and Investigative Andrology. New York, NY: Springer-Verlag; 1981 .
Marmar JL, Katz S, Praiss DE, DeBenedictis TJ. Semen zinc levels in infertile and postvasectomy patients and patients with prostatitis. Fertil Steril. 1975; 26: 1057 -1063.[Medline]
Martikainen P, Sannikka E, Suominen J, Santti R. Glucose content as a parameter of semen quality. Arch Androl. 1980; 5: 337 -343.[Medline]
Mauss J, Borsch G, Torok L. Differential diagnosis of low or absent seminal fructose in man. Fertil Steril. 1974; 25: 411 -415.[Medline]
Mawson CA, Fischer MI. Zinc in aspermic human semen. Nature. 1956;177: 190 .[Medline]
Meacham R. Perspectives and editorials: from Androlog. J
Androl. 2002;23: 330
-331.
Mendiratta R, Dasgupta PR, Sheth AR. Vasectomy and biochemical composition of human seminal plasma. Indian J Exp Biol. 1980;18: 409 -410.
Montagnon D, Clavert A, Cranz C. Fructose, proteins and coagulation in human seminal plasma. Andrologia. 1982; 14: 434 -439.[Medline]
Moon KH, Bunge RG. Observations on the biochemistry of human semen. Fertil Steril. 1968; 19: 186 -191.[Medline]
Mortimer D. Practical Laboratory Andrology. New York, NY: Oxford University Press; 1994.
Mortimer D, Templeton AA, Lenton EA, Coleman RA. Semen analysis parameters and their interrelationships in suspected infertile men. Arch Androl. 1982; 8: 165 -171.[Medline]
Moulik S, Gopalkrishnan K, Hinduja I, Shahani SK. Presence of sperm
antibodies and association with viscosity of semen. Hum
Reprod. 1989;4: 290
-291.
Nag A, Chaudhuri N. Electrolyte content of human seminal fluid at different states of fertility. Indian J Exp Biol. 1978; 16: 954 -956.[Medline]
Nag A, Chaudhuri N, Nag PK. Relative viscosity of human seminal fluid: influence of sperm concentration, motility and biochemical ingredients. Andrologia. 1979; 11: 478 -482.
Nagy F, Pendergrass PB, Bowen DC, Yeager JC. A comparative study of
cytological and physiological parameters of semen obtained from alcoholics and
non-alcoholics. Alcohol Alcohol. 1986; 21: 17
-23.
Nikkanen V. The effects of vasectomy on viscosity, pH and volume of semen in man. Andrologia. 1979; 11: 123 -125.[Medline]
Nun S, Musacchio I, Epstein JA. Variations in seminal plasma constituents from fertile, subfertile, and vasectomized azoospermic men. Fertil Steril. 1972; 23: 357 -360.[Medline]
Oforofuo IAO, Onakewhor JUE, Enuman J. Fructose concentration in seminal fluids and the deoxyribonucleic acid content of spermatozoa from infertile human males. Afr J Reprod Health. 1997; 1: 89 -96.[Medline]
Owen DH, Dunmire EN, Plenys AM, Katz DF. Factors influencing non-oxynol-9 permeation and bioactivity in cervical mucus. J Control Release. 1999a;60: 23 -34.[CrossRef][Medline]
Owen DH, Geonnotti AR, Kieweg SL, Schnaare R, Katz DF. Mechanistic analysis of deployment of prototype formulations for delivery of topical anti-HIV agents to the female reproductive tract . Baltimore, Md: Annual Meeting of the American Association of Pharmceutical Sciences; 2004.
Owen DH, Katz DF. A vaginal fluid simulant. Contraception. 1999b; 59: 91 -95.[CrossRef][Medline]
Owen DH, Peters JJ, Katz DF. Rheological properties of contraceptive gels. Contraception. 2000; 62: 321 -326.[CrossRef][Medline]
Owen DH, Peters JJ, Katz DF. Comparison of the rheological properties of Advantage-S and Replens. Contraception. 2001; 64: 393 -396.[CrossRef][Medline]
Owen DH, Peters JJ, Lavine ML, Katz DF. Effect of temperature and pH on contraceptive gel viscosity. Contraception. 2003; 67: 57 -64.[CrossRef][Medline]
Papadimas J, Bontis J, Ikkos D, Mantalenakis S. Seminal plasma zinc and magnesium in infertile men. Arch Androl. 1983; 10: 261 -268.[Medline]
Paz GF, Sofer A, Hominnai ZT, Kraicer PF. Human semen analysis: seminal plasma and prostatic fluid compositions and their interrelations with sperm quality. Int J Fertil. 1977; 22: 140 -147.[Medline]
Peterson RN, Freund M. Factors affecting fructose utilization and lactic acid formation by human semen. The role of glucose and pyruvic acid. Fertil Steril. 1971; 22: 639 -644.[Medline]
Polak B, Daunter B. Osmolarity of human seminal plasma. Andrologia. 1984; 16: 224 -227.[Medline]
Polak B, Daunter B. Seminal plasma biochemistry. IV: Enzymes involved in the liquefaction of human seminal plasma. Int J Androl. 1989;12: 187 -194.[Medline]
Polakoski KL, Syner FN, Zaneveld LJD. Biochemistry of human seminal plasma. In: Hafez ESE, ed. Human Semen and Fertility Regulation in Men. St Louis, Mo: CV Mosby Company; 1976: 133 -143.
Ponchietti R, Raugei A, Lanciotti E, Ademollo B, Galvan P, Poggini G. Calcium, zinc, magnesium, concentration in seminal plasma of infertile men with prostatitis. Acta Eur Fertil. 1984; 15: 283 -285.[Medline]
Prien SD, Lox CD, Messer RH, DeLeon FD. Seminal concentrations of total and ionized calcium from men with normal and decreased motility. Fertil Steril. 1990; 54: 171 -172.[Medline]
Pryde J. Sugar of human semen. Nature. 1946; 157: 660 .
Purvis K, Magnus O, Morkas L, Abyholm T, Rui H. Ejaculate composition after masturbation and coitus in the human male. Int J Androl. 1986;9: 401 -406.[Medline]
Quinn PJ, White IG, Wirrick BR. Studies of the distribution of the major cations in semen and male accessory secretions. J Reprod Fertil. 1965;10: 379 -388.
Raboch J, Skachova J. The pH of human ejaculate. Fertil Steril. 1965;16: 252 -256.[Medline]
Ray A, Chaudhuri N, Nag PK. Inconsistent influence of sperm concentration on the viscosity of human seminal fluid. Indian J Exp Biol. 1977;15: 792 -794.[Medline]
Rehan NE, Sobrero AJ, Fertig JW. The semen of fertile men: statistical analysis of 1300 men. Fertil Steril. 1975; 26: 492 -502.[Medline]
Rosecrans RR, Jeyendran RS, Perez-Pelaez M, Kennedy WP. Comparison of biochemical parameters of human blood serum and seminal plasma. Andrologia. 1987; 19: 625 -628.[Medline]
Rossi S, Bonferoni C, Lippoli G, Bertoni M, Ferrari F, Caramella C, Conte U. Influence of mucin type on polymer-mucin rheological interactions. Biomaterials. 1995; 16: 1073 -1079.[CrossRef][Medline]
Schirren C. Ferilitatsstorungen des Mannes. Diagnosik, biochemie des spermplasmas. Hormontherapie. Stuttgart, Germany: F Enke; 1961.
Schirren C, Laudahn G, Hartmann E, Heinze I. Studies of the correlation of morphological and biochemical parameters in human ejaculate in various andrological diagnoses; 2nd report: biochemical parameters. Andrologia. 1977; 9: 95 -105.[Medline]
Schoenfeld C, Amelar RD, Dubin L, Numeroff M. Prolactin, fructose, and zinc levels found in human seminal plasma. Fertil Steril. 1979;32: 206 -208.[Medline]
Searcy RL, Simms NM. A practical approach for acid-base characterization of human semen. Int J Fertil. 1967; 12: 329 -334.[Medline]
Shedlovsky L, Belcher D, Levenstein I. Titrations of human seminal
fluid with acids and alkalis and their effects on the survival of sperm
motility. Am J Physiol. 1942; 136: 535
-541.
Sheth AR, Rao SS. Fructose and fructolysis in human semen determined chromatographically. Experientia. 1959; 15: 314 -316.[CrossRef][Medline]
Sheth AR, Rao SS. Potassium levels in human semen with reference to sperm motility. Experientia. 1962a; 18: 324 -325.[CrossRef][Medline]
Sheth AR, Rao SS. Fructose levels in human semen determined chromatographically. Indian J Med Sci. 1962b; 16: 709 -716.[Medline]
Sheth AR, Rao SS. Potassium levels of human semen. Indian J Med Sci. 1968; 56: 1806 -1807.
Skandhan KP, Mazumdar BN. Correlation of sodium and potassium in human seminal plasma with fertilizing capacity of normal and infertile subjects. Andrologia. 1981; 13: 147 -154.[Medline]
Skandhan KP, Mehta YB, Chary TM, Achar MVS. Semen electrolytes in normal and infertile subjects. I. Sodium, potassium, calcium and magnesium. J Obstet Gynecol India. 1978; 27: 286 -294.
Smith R, Vantman D, Ponce J, Escobar J, Lissi E. Total antioxidant
capacity of human seminal plasma. Hum Reprod. 1996; 11: 1655
-1660.
Sorensen MB, Bergdahl IA, Hjollund NHI, Bonde JPE, Stoltenberg M,
Ernst E. Zinc, magnesium and calcium in human seminal fluid: relations to
other semen parameters and fertility. Mol Hum Reprod. 1999; 5: 331
-337.
Srivastava A, Chopra SK, Dasgupta PR. Biochemical analysis of human seminal plasma. II. Protein, non-protein nitrogen, urea, uric acid and creatine. Andrologia. 1984; 16: 265 -268.[Medline]
Stankovic H, Mikac-Devic D. Zinc and copper in human semen. Clin Chim Acta. 1976; 70: 123 -126.[CrossRef][Medline]
Stegmayr B, Berggren PO, Ronquist G, Hellman B. Calcium, magnesium, and zinc contents in organelles of prostatic origin in human plasma. Scand J Urol Nephrol. 1982; 16: 199 -203.[Medline]
Tauber PF, Zaneveld LJD, Propping D, Schumacher GFB. Components of human split ejaculates. I. Spermatozoa, fructose, immunoglobulins, albumin, lactoferrin, transferrin and other plasma proteins. J Reprod Fertil. 1975;43: 249 -267.
Tjioe DY, Oentoeng S. The viscosity of human semen and the percentage of motile spermatozoa. Fertil Steril. 1968; 19: 562 -565.[Medline]
Tomaszewski L, Konarska L, Janczewski Z, Skarzynska E, Lebioda K, Hryckiewicz L. Fructosamine in human and bovine semen. Life Sci. 1992;50: 181 -185.[CrossRef][Medline]
Tyler ET. Seminal fructose studies in infertility. Fertil Steril. 1955; 6: 247 -258.[Medline]
Tynen J. Observations on specimens of human semen. J Contraception. 1939;4: 125 -127.
Umeyama T, Ishikaa H, Takeshima H, Yoshii S, Koiso K. A comparative study of seminal trace elements in fertile and infertile men. Fertil Steril. 1986; 46: 494 -499.[Medline]
Vaishwanar PS, Abhyankar HN. Acid phosphatase and pH in human semen. Indian J Exp Biol. 1971; 9: 261 -263.[Medline]
Velazquez A, Pedron N, Delgado NM, Rosado A. Osmolality and conductance of normal and abnormal human seminal plasma. Int J Fertil. 1977;22: 92 -97.[Medline]
Verma PK, Singh JN, Quadros M. Modifications in the seminal protein pattern and concentration among infertile men. Indian J Med Sci. 1993;47: 61 -67.[Medline]
Videla E, Blanco AM, Galli ME, Fernandez-Collazo E. Human seminal biochemistry: fructose, ascorbic acid, citric acid, acid phosphatase and their relationship with sperm count. Andrologia. 1981; 13: 212 -214.[Medline]
Wolters-Everhardt E, Dony JMJ, Lemmens WAJG, Doesbury WH, De Pont JJHHM. Buffering capacity of human semen. Fertil Steril. 1986;46: 114 -119.[Medline]
Wolters-Everhardt E, Dony JMJ, Peters WHM, De Pont JJHHM. Buffering substances of human semen. Fertil Steril. 1987; 48: 159 -161.[Medline]
Wood BJ, Lawrence DM, McGarrigle HHG. Similar zinc levels in seminal fluid from normospermic, oligospermic and azoospermic men. Clin Chim Acta. 1982; 123: 329 -332.[CrossRef][Medline]
World Health Organization (WHO), ed. WHO Laboratory Manual for the Examination of Human Semen and Sperm-Cervical Mucus Interaction. 4th ed. New York, NY: Cambridge University Press; 1999 .
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