ISSN:
0003-276X
Keywords:
Life and Medical Sciences
;
Cell & Developmental Biology
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Medicine
Notes:
Unilateral ovariectomy of hamsters on day 1 of pregnancy resulted in an increase in weight of the remaining ovary by day 4, primarily by increasing the number of antral follicles. The ovulability of these follicles was tested by injecting 20 IU human chorionic gonadotropin (HCG) on day 12 of pregnancy. Following this treatment, the unilaterally ovariectomized animals ovulated 29.4 eggs whereas intact animals ovulated 16.6 eggs per ovary. In both instances, the number of antral follicles ovulated by HCG was between 40% and 50% of the number present. Luteal weight was unaltered by semispaying, indicating that the regulation of corpus luteum growth does not fit a negative feedback system.The ability of exogenous steroids to prevent ovarian compensation was assessed by injecting either progesterone (2 mg) or estradiol cyclopentylpropionate (1 μg) daily from days 8 to 11 of pregnancy. Either steroid injected into the semispayed hamsters prevented the expected increase in the remaining ovary in weight, follicular development and the ovulatory response to HCG. The same hormonal treatment of intact, pregnant animals slightly increased mean ovarian weight but did not affect follicular development.These results suggest that unilateral ovariectomy of the pregnant hamster, by decreasing peripheral level of ovarian steroids, partially reduces the inhibition of gonadotropin secretion and therefore leads to ovarian compensation.
Additional Material:
4 Tab.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/ar.1091710202
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