Neonatal treatment of male rats with a gonadotropin-releasing hormone antagonist impairs ejaculation and fertility.
Pituitary-gonadal suppression of neonatal male rats with a gonadotropin-releasing hormone antagonist N-Ac-D-Nal(2)1,D-p-Cl-Phe2,D-Trp3,D-hArg(Et2)6,D-Ala10 -GnRH (RS 68439; Syntex; 2 mg/kg/day) during days 1-10 of life resulted in infertility of adult animals, when studied at the age of 90, 115 and 150 days. Numbers of fertile animals per rats tested at these ages were 1/10, 2/14 and 4/14, respectively, in the antagonist treated animals (vs. 8/10, 9/13 and 9/13 in controls; p less than 0.01-0.05). The numbers of mounts and intromissions were unaffected by the antagonist treatment, but none of the treated animals (n = 10) ejaculated in four subsequent behavior tests. However, if the vaginal smears were checked in a group of rats after caging the males separately with a normal female for 8 days before the behavior tests, each male had ejaculated but the females were not fertilized. When the neonatally GnRH antagonist-treated rats were followed in the long-term, fertility slowly recovered, and at the age of 220 and 350 days, the number of successful pregnancies was similar to that of age-matched controls. It is concluded that short-term neonatal pituitary-gonadal suppression with GnRH antagonist results in impaired ejaculation and infertility of adult male rats, but fertility slowly recovers within a year.
Kolho
K L
KL
Department of Physiology, University of Turku, Finland.
Huhtaniemi
I
I
D000375:Aging / Q000502:physiology*; D000818:Animals; D000831:Animals, Newborn / Q000502:physiology*; D005298:Fertility / Q000187:drug effects*; D007987:Gonadotropin-Releasing Hormone / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000037:antagonists & inhibitors / Q000494:pharmacology; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D012726:Sexual Behavior, Animal / Q000187:drug effects*
C043699:detirelix; D007987:Gonadotropin-Releasing Hormone