Delayed implantation induced by fadrozole hydrochloride in rats.
The effect of aromatase inhibitors on the implantation process is not well known. This study examined the anti-implantation action in rats of a nonsteroidal aromatase inhibitor of high specific activity, fadrozole hydrochloride (Fad). Continuous subcutaneous infusion of Fad at 300 microg/day from Day 1 (the day of sperm detection) through Day 7 of pregnancy using a mini-osmotic pump was found to delay the initiation of implantation by 1 or 2 days with no negative effects on embryonic viability. The Fad treatment delayed preimplantation embryo development and zona shedding by embryos. The treatment also delayed the period of maximum sensitivity to a decidualizing stimulus (intraluminal infusion of sesame oil) by 2 days. The results show that continuous treatment with Fad has multiple anti-implantation effects in rats.
Tamada
H
H
Laboratory of Theriogenology, Graduate School of Agriculture and Biological Sciences, Osaka Prefecture University, Sakai, 599-8531, Osaka, Japan. tamada@vet.osakafu-u.ac.jp
Mizuta
Y
Y
Kawate
N
N
Inaba
T
T
Sawada
T
T
D000818:Animals; D047072:Aromatase Inhibitors; D001755:Blastocyst / Q000187:drug effects; D003282:Contraceptives, Postcoital, Hormonal / Q000494:pharmacology; D010064:Embryo Implantation / Q000187:drug effects*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D017316:Fadrozole / Q000494:pharmacology*; D005260:Female; D005328:Fetal Viability / Q000187:drug effects; D020567:Fetal Weight / Q000187:drug effects; D011247:Pregnancy; D051381:Rats; D017207:Rats, Sprague-Dawley
D047072:Aromatase Inhibitors; D003282:Contraceptives, Postcoital, Hormonal; D004791:Enzyme Inhibitors; D017316:Fadrozole