title: Time course of endocrine changes in the hypophysis-gonad axis induced by hypobaric hypoxia in male rats.
abstract: 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.
authors.affiliation: Universidad Arturo Prat-Centro de Investigaciones del Hombre del Desierto, Iquique, Chile. jorge.farias@unap.cl
authors.forename: Jorge Gonzalo
authors.initials: JG
authors.lastname: Farias
authors.forename: Eduardo
authors.initials: E
authors.lastname: Bustos-Obregón
authors.forename: Pablo Jose
authors.initials: PJ
authors.lastname: Tapia
authors.forename: Eduardo
authors.initials: E
authors.lastname: Gutierrez
authors.forename: Andrea
authors.initials: A
authors.lastname: Zepeda
authors.forename: Camila
authors.initials: C
authors.lastname: Juantok
authors.forename: Gonzalo
authors.initials: G
authors.lastname: Cruz
authors.forename: Gustavo
authors.initials: G
authors.lastname: Soto
authors.forename: Julio
authors.initials: J
authors.lastname: Benites
authors.forename: Juan Guillermo
authors.initials: JG
authors.lastname: Reyes
mesh_terms: 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*
chemical_list: D013739:Testosterone; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone