| Study |
Objective |
Parameter(s) Measured |
Outcome |
Comments |
|
| Rajasekaran et al, 2001 |
In vitro study of human cavernosal smooth muscle exposed to increasing
concentrations of sodium nitroprusside to measure the effect of increased
levels of NO donors |
Thymidine incorporation for DNA synthesis; 8-iso PGF2 for
oxidative stress; ATP levels for mitochondrial function |
Cell growth (DNA synthesis) and decreased DNA synthesis; increase levels of
8-iso PGF2; decreased ATP levels |
SNP  oxidative stress induced cavernosal smooth muscle damage. |
| Khan et al, 2001 |
In vitro study of rabbit cavernosal strips (n = 9) exposed to NO or
peroxynitrite |
Smooth-muscle relaxation |
Peroxynitrite is significantly less potent than NO |
Peroxynitrite is a weak relaxant compared with NO. |
| Ryu et al, 2003 |
Comparison of rats with streptozotocin-induced short-term DM (duration, 22
weeks), rats with long-term DM (duration, 38 weeks), and age-matched controls |
Intracavernosal glutathione level |
Decreased ICP and glutathione levels in rats with DM; decreased ICP levels in
rats with long-term DM, compared with those with short-term DM |
Oxidative stress may be a contributing factor for ED in diabetes mellitus. |
| De Young et al, 2004 |
In vivo and in vitro studies of healthy rats vs rats with
streptozotocin-induced diabetes; rats received no treatment (controls), oral
peanut oil (20 IU/d of vitamin E), sildenafil (5 mg/d), or vitamin E plus
sildenafil |
ICP; NOS |
Significantly higher ICP and NOS levels in the group that received combination
treatment, compared with controls |
Sildenafil effect enhanced by vitamin E. |
| Jones et al, 2005 |
Comparison of hyperhomocysteinemic rats (n = 6) with healthy controls (n = 6) |
Carbachol-mediated cavernosal smooth-muscle relaxation; effect of SOD or
catalase |
Impaired relaxation in hyperhomocysteinemic rabbits; normalization of
relaxation with receipt of SOD or catalase |
ROS decreases the NO-dependant relaxation. |
|
| *DM indicates diabetes mellitus; ICP, intracavernosal pressure; NO, nitric
oxide; NOS, NO synthase; OS, oxidative stress; PGF, prostaglandin F; and SOD,
superoxide dismutase |
