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.
Department of Surgery, University of Texas Southwestern Medical Center, Dallas 75235-9031.
D A
DA
Husmann
M J
MJ
McPhaul
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