Mechanisms of reproductive deficiency in male rats treated neonatally with a gonadotrophin-releasing hormone antagonist.
It is well known that males injected neonatally with oestradiol or antiserum or antagonists (ANT) against gonadotrophin-releasing hormone (GnRH) show multiple reproductive disorders. In the present work, in males treated neonatally with GnRH-ANT, we have analysed: (1) whether the impairment of reproductive function can be blocked by simultaneous treatment with gonadotrophins, (2) the possible differences in the effects of GnRH-ANT injected before or after the proliferation of Sertoli cells which takes place between days 1 and 15 of age, and (3) the mechanism(s) for the increased FSH secretion observed in adulthood. Experimental designs included: administration of GnRH-ANT between days 1 and 16 or 15 and 30 of age, simultaneous administration of gonadotrophins and GnRH-ANT to neonatal males, and measurement of FSH secretion after orchidectomy or specific destruction of Leydig cells with ethylene dimethane sulphonate (EDS) in adult males treated neonatally with GnRH-ANT. The principal new data presented in our studies are the following: (1) delayed puberty was observed not only in males injected neonatally with GnRH-ANT, but also in those injected with gonadotrophins or with GnRH-ANT and gonadotrophins, (2) the decreased fertility and increased FSH secretion observed in adult males treated neonatally with GnRH-ANT were normalized by simultaneous administration of GnRH-ANT and gonadotrophins, and (3) the increased FSH secretion in adult males treated neonatally with GnRH-ANT remained after EDS or orchidectomy, suggesting that mechanisms other than decreased inhibin secretion were involved in the increased secretion of FSH.
Department of Physiology, Faculty of Medicine, University of Córdoba, Spain.
L
L
Pinilla
P
P
Garnelo
M
M
Tena-Sempere
F
F
Gaytan
E
E
Aguilar
D000818:Animals; D000831:Animals, Newborn; D005298:Fertility / Q000187:drug effects*; D005640:Follicle Stimulating Hormone / Q000378:metabolism* / Q000494:pharmacology; D007987:Gonadotropin-Releasing Hormone / Q000031:analogs & derivatives* / Q000037:antagonists & inhibitors* / Q000494:pharmacology; D007985:Leydig Cells / Q000187:drug effects; D007986:Luteinizing Hormone / Q000494:pharmacology; D008297:Male; D008698:Mesylates / Q000494:pharmacology; D009919:Orchiectomy; D051381:Rats; D017208:Rats, Wistar; D012741:Sexual Maturation / Q000187:drug effects*
D008698:Mesylates; D007987:Gonadotropin-Releasing Hormone; C042691:LHRH, N-acetyl-(4-chlorophenylalanyl)(1)-(4-chlorophenylalanyl)(2)-tryptophyl(3)-arginyl(6)-alanine(10)-; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone; C002994:ethylene dimethanesulfonate