Time-specific androgen blockade with flutamide inhibits testicular descent in the rat.
Inhibition of androgen action by flutamide, a nonsteroidal antiandrogen, blocked testicular descent in 40% of the testes exposed to this agent continuously from gestational day 13 through postpartal day 28. By contrast, only 11% of the testes failed to descend when blocked by 5 alpha-reductase inhibitors during the same period. Flutamide administration over narrower time intervals (gestational day 13-15, 16-17, or 18-19) revealed maximal interference with testicular descent after androgen inhibition during gestational days 16-17. No significant differences in testicular or epididymal weights were evident between descended and undescended testes; furthermore, no correlation was detected between the presence of epididymal abnormalities and testicular descent. These findings indicate that androgen inhibition during a brief period of embryonic development can block testicular descent. The mechanism through which this inhibition occurs remains to be elucidated.
Husmann
D A
DA
Department of Surgery, University of Texas Southwestern Medical Center, Dallas 75235-9031.
McPhaul
M J
MJ
D058891:5-alpha Reductase Inhibitors; D000736:Androstenes / Q000494:pharmacology*; D000818:Animals; D001378:Azasteroids / Q000494:pharmacology*; D003456:Cryptorchidism / Q000139:chemically induced*; D005314:Embryonic and Fetal Development; D005260:Female; D018120:Finasteride; D005485:Flutamide / Q000008:administration & dosage / Q000494:pharmacology*; D008297:Male; D008431:Maternal-Fetal Exchange; D011247:Pregnancy; D051381:Rats; D011919:Rats, Inbred Strains; D013737:Testis / Q000187:drug effects / Q000196:embryology / Q000254:growth & development* / Q000473:pathology
D058891:5-alpha Reductase Inhibitors; D000736:Androstenes; D001378:Azasteroids; D018120:Finasteride; D005485:Flutamide