Atsushi Tohei, Satoshi Sakamoto and Hiroshi Kogo*
Department of Pharmacology, Tokyo University of Pharmacy and Life Science,
Hachioji, Tokyo 192-0392, Japan
*Corresponding author.ﾊﾊFAX:+81-426-76-4526
E-mail: kogo@ps.toyaku.ac.jp
Abstract: We have previously reported that dexamethasone increased
follicle-stimulating hormone (FSH) secretion via suppression of inhibin
in immature female rats. In the present study, we investigated the effects
of dexamethasone or triamcinolone on follicular development and ovarian
functions (estradiol and inhibin secretion) in equine chorionic gonadotropin
(eCG)-primed immature female rats. Dexamethasone significantly increased
the number of ovulated oocytes in immature female rats treated with 5ﾊi.u.
eCG. Serum concentration of FSH in eCG-treated female rats was increased
by administration of dexamethasone or triamcinolone, showing the peak value
at 9ﾊh after its administration, although the levels of inhibin markedly
decreased at that time. Serum concentrations of inhibin and estradiol in
eCG-treated female rats increased at 24ﾊh after administration of dexamethasone
or triamcinolone. These results demonstrate that dexamethasone or triamcinolone
increases FSH secretion, and the excess amount of FSH strongly stimulates
follicular development cooperating with exogenous eCG.
Keywords: Dexamethasone, Triamcinolone, Follicle-stimulating hormone,
Follicular development, Immature female rat
Copyrightｩ The Japanese Pharmacological Society 2000
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