REPRODUCTIVE ORGANS AND ANTERIOR HYPOPHYSIS OF NEONATALLY ANDROGENIZED FEMALE RATS
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概要
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In female rats, daily injections of high dose testosterone propionate (TP) for periods of varying lengths from the day of birth elicited persistent changes in the secretion of gonadotropins from the anterior hypophysis and in structure and hormone sensitivity of the uterus and vagina. The ovaries varied in structure, from anovulatory polyfollicular ovaries to minute ones with neither vesicular follicles nor corpora lutea, according to the length of TP injection period. In rats having the latter type ovaries, hypophysectomy evoked no perceptible changes in ovarian structure. Ovariectomy or ovariectomy followed by low dose estradiol injections (0.1μg daily for 3 days) resulted in no significant changes in uterine weight in rats given TP injections over prolonged neonatal periods, although high doses of estradiol (10μg daily) caused a definite increase in uterine weight in similar animals. The uterine epithelium was thickened, pseudostratified or stratified in a majority of the intact androgenized rats. In a good many animals, the epithelium had metaplastic areas. Following ovariectomy, the uterine epithelium was lowered at least in some rats and the metaplastic areas disappeared, although it might remain pseudostratified or stratified for at least 7 days. Injections of estradiol resulted in a marked hypertrophy of the uterine epithelium and occasional incidence of metaplasia in the ovariectomized rats. The uterine stroma was not stimulated to grow by injections of low dose estradiol in rats subjected to prolonged neonatal androgenization and this might account for the failure of estradiol injections to increase the uterine weight in such animals. In the vagina of androgenized rats, three zones could be distinguished by the state of the epithelium. The epithelium lining the proximal zone varied considerably in structure among different individuals, largely according to the length of neonatal TP treatment. In some rats it was two-layered, while in others it was stratified and squamous, with mucified or cornifiedlayers on the surface. The middle zone had a multilayered non-squamous epithelium and the distal zone bore a squamous cornified one. The zonation was not obliterated by hypophysectomy followed by ovariectomy and adrenalectomy. The epithelium of the proximal zone was the only portion of the vaginal epithelium capable of responding to estrogen by cornification and to estrogen plus progesterone by mucification. At prolonged intervals after ovariectomy, the epithelium of this zone was reduced in thickness, uniformly consisting of 2 layers of cells. The epithelia of the middle and distal zones were stratified non-squamous and cornified, respectively, without reference to the presence or absence of ovarian hormones. The vagina of androgenized rats failed to have its orifice in the normal site, the cornified distal zone opening to the exterior by a minute aperture on the clitoris or communicating with the urethra near its distal end. In the anterior hypophysis of females which had received TP injections over a 30-day neonatal period, gonadotropin secreting basophilic cells were markedly reduced in number or totally absent. However, the secretion of prolactin by the hypophysis was chronically depressed by the hypothalamus in these rats as in normal females. The anterior hypophysis disconnected from the hypothalamus by transplantation, consisting largely of erythrosinophilic cells, secreted the hormone actively.
- 東京女子大学の論文
- 1968-03-25