Time course of endocrine changes in the hypophysis-gonad axis induced by hypobaric hypoxia in male rats.
Chronic hypobaric hypoxia (CHH) induces a decrease in sperm output and spermatogenesis in male rats. The mechanisms that underlie these changes in testicular function are unknown and could involve changes in the hypophysis-gonad axis. We have tested the hypothesis that changes take place in the endocrine status (FSH, follicle stimulating hormone; LH, luteinizing hormone; testosterone) of rats subjected to CHH. Male Wistar rats were maintained under normobaric or hypobaric conditions (428 torr, 4,600 m). On days 0, 5, 15 and 30 post-exposure, 12 rats were anesthetized, their body weights were measured and blood samples were collected. The testicles were fixed in 4% formaldehyde and processed for histological analysis. In this time course, the FSH levels rose by day 5 post-exposure. On subsequent days, the FSH levels decreased in rats subjected to CHH with a tendency to remain higher than the normoxic group. The LH plasma levels decreased in rats exposed to CHH. Consistent with the decrease in LH levels, the plasma testosterone level decreased significantly after 30 days of CHH exposure. Integrated analysis of hormonal changes in rats subjected to CHH and the body dehydration that occurs in HH allows us to conclude that the effects of CHH on spermatogenesis may be partially related to changes in the hypophysis-gonad hormonal axis.
Farias
Jorge Gonzalo
JG
Universidad Arturo Prat-Centro de Investigaciones del Hombre del Desierto, Iquique, Chile. jorge.farias@unap.cl
Bustos-Obregón
Eduardo
E
Tapia
Pablo Jose
PJ
Gutierrez
Eduardo
E
Zepeda
Andrea
A
Juantok
Camila
C
Cruz
Gonzalo
G
Soto
Gustavo
G
Benites
Julio
J
Reyes
Juan Guillermo
JG
D000818:Animals; D003681:Dehydration / Q000503:physiopathology; D004435:Eating / Q000502:physiology*; D005640:Follicle Stimulating Hormone / Q000097:blood*; D000860:Hypoxia / Q000097:blood* / Q000503:physiopathology; D007248:Infertility, Male / Q000503:physiopathology; D007986:Luteinizing Hormone / Q000097:blood*; D008297:Male; D010902:Pituitary Gland / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D013091:Spermatogenesis / Q000502:physiology; D013737:Testis / Q000378:metabolism; D013739:Testosterone / Q000097:blood*
D013739:Testosterone; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone