[The role of prolactin on sexual maturation of female rat].
The role of prolactin (PRL) in sexual maturation of immature female rats was examined in drug induced hyper-or hypoprolactinemic models. 1. In order to examine the role of PRL before the third week after birth, at which the serum PRL level of female rats is known to be low under physiological conditions, hyperprolactinemia was induced by daily subcutaneous injections of sulpiride from day 10 to day 20. Ovarian and uterine weights, serum hormone levels and in vitro estradiol (E2) release from removed ovary were evaluated on day 15 and day 20. The inhibition of uterine growth on both days a low serum E2 concentration on day 20 and inhibition of in vitro ovarian E2 release were demonstrated as the result of sulpiride treatment. 2. In order to examine the role of PRL after the fourth week, when the serum PRL level is known to become high, hyper- or hypoprolactinemia was induced from day 22 by per os administration of sulpiride or bromocriptine. Timing of the onset of puberty weights of the ovary, uterus and adrenal gland and serum hormone levels at the onset of puberty were evaluated. In the sulpiride treated group the timing of the onset of puberty was not affected and lower adrenal gland weight and a low serum FSH concentration were observed. In the bromocriptine treated group the timing of the onset of puberty was delayed and greater adrenal gland weight was observed. Serum hormone levels were not affected. These results suggest that (i) prolactin could have an inhibitory effect on sexual maturation before the 3rd week.(ABSTRACT TRUNCATED AT 250 WORDS)
Tozawa
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Department of Obstetrics and Gynecology, Tohoku University School of Medicine, Sendai.
D000818:Animals; D001835:Body Weight / Q000187:drug effects; D001971:Bromocriptine / Q000494:pharmacology; D004958:Estradiol / Q000378:metabolism; D005260:Female; D009929:Organ Size / Q000187:drug effects; D010053:Ovary / Q000502:physiology; D011388:Prolactin / Q000097:blood / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012741:Sexual Maturation / Q000502:physiology*; D013469:Sulpiride / Q000494:pharmacology
D001971:Bromocriptine; D004958:Estradiol; D013469:Sulpiride; D011388:Prolactin