Journal of Andrology, Vol. 26, No. 6, November/December 2005
Copyright © American Society of Andrology
DOI: 10.2164/jandrol.05013
Increase in Testicular Temperature and Vascularization Induced by Hypobaric Hypoxia in Rats
JORGE G. FARÍAS*,
,
EDUARDO BUSTOS-OBREGÓN
AND
JUAN G. REYES
,||
From the * Laboratorio de Biomedicina de Altura,
Instituto de Estudios de la Salud, Universidad Arturo Prat, Iquique, Chile;
Centro de Investigaciones del Hombre del
Desierto, CIHDE, Iquique, Chile;
Instituto de
Química, Pontificia Universidad Cátolica de Valparaíso,
Valparaíso, Chile; || Department of
Physiology, University of Alabama at Birmingham, Birmingham, Alabama; and
Facultad de Medicina, Universidad de Chile,
Santiago, Chile.
|
Correspondence to: Jorge G. Farías, Laboratorio de Biomedicina de
Altura, Instituto de Estudios de la Salud, Universidad Arturo Prat, Av Arturo
Prat 2120, Iquique, Chile (e-mail:
jorge.farias{at}unap.cl). |
The exposure of male rats to continuous chronic hypobaric hypoxia (HH) and
intermittent chronic hypobaric hypoxia induced evident changes in testicular
morphology and spermatogenic cell metabolism. The mechanisms that underlie
these changes under HH are not known. In this work, we have tested the
hypothesis that in rats subjected to HH, the testis undergoes changes in
vascularization leading to changes in temperature homeostasis. Male Wistar
rats (247 ± 16 g) were maintained in normobaric or hypobaric (428 torr,
equivalent to 4600 m a.s.l) conditions. At days 0, 5, 15, and 30 postexposure,
12 rats were anesthetized with ketamine, and the intratesticular temperature
was determined. These rats were subsequently sacrificed and the testicles were
fixed in formaldehyde and processed for routine histological analysis. Our
results showed that the height of the seminiferous epithelium decreased
significantly at day 5 posthypoxia and thereafter, indicating a decreased
spermatogenesis. Intratesticular temperature increased (1.5°C) and
remained high after 5 days of hypoxia exposure. Correlated with these changes,
histometrical analysis of the number of blood vessels in the testicular
interstitium was significantly increased by day 5 and afterwards.
Morphological classification of interstitial blood vessels indicates a
transition from capillaries to larger vessels as the hypoxia exposure
progresses.
Key words: Reproduction, hyperthermia, angiogenesis, high altitude
Copyright © 2005 by The American Society of Andrology.