title: Voluntary exercise increases gonadotropin secretion in male Golden hamsters.
abstract: To determine the effect of voluntary exercise and food restriction on reproductive hormone secretion, 48 adult male hamsters were placed in cages with (EX) or without (SED) running wheels. One-half of the animals in each exercise group was fed ad libitum, and the other half was food restricted to reduce their body weight to 90 g over 4 wk. After 10 wk, the EX ad libitum-fed group had much larger testes and much higher serum follicle-stimulating hormone and testosterone levels than the other three groups, but these values in the EX food-restricted hamsters were similar to those in the SED food-restricted group. In experiment 2, 20 adult male hamsters were castrated and later implanted with silicone rubber capsules containing testosterone. Two weeks after implantation of the capsules, the serum follicle-stimulating hormone levels were higher in the EX than in the SED group of testosterone-treated hamsters, but not in animals receiving blank capsules. These data suggest that exercise increases gonadotropin secretion by inhibiting the negative feedback of testosterone.
authors.affiliation: Department of Physiology, Providence Hospital, Southfield 48037, USA.
authors.forename: D R
authors.initials: DR
authors.lastname: Pieper
authors.forename: H Y
authors.initials: HY
authors.lastname: Ali
authors.forename: L L
authors.initials: LL
authors.lastname: Benson
authors.forename: M D
authors.initials: MD
authors.lastname: Shows
authors.forename: C A
authors.initials: CA
authors.lastname: Lobocki
authors.forename: M G
authors.initials: MG
authors.lastname: Subramanian
mesh_terms: D000818:Animals; D006224:Cricetinae; D004343:Drug Implants; D005640:Follicle Stimulating Hormone / Q000097:blood; D005508:Food Deprivation; D006062:Gonadotropins / Q000378:metabolism*; D007986:Luteinizing Hormone / Q000097:blood; D008297:Male; D008647:Mesocricetus; D009919:Orchiectomy; D009929:Organ Size; D005082:Physical Exertion; D013737:Testis / Q000033:anatomy & histology; D013739:Testosterone / Q000097:blood / Q000494:pharmacology; D014836:Volition
chemical_list: D004343:Drug Implants; D006062:Gonadotropins; D013739:Testosterone; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone