Gonadotropin Secretion in Lactating Mice. ∗

Abstract

Summary

1. Intraocular ovarian isotransplants in ovariectomized lactating BALB/c mice showed little growth and developed only vesicular follicles in the first part of the lactation interval. The first vaginal estrus occurred between 17 and 21 days after parturition, followed by abrupt appearance of pink or red corpora lutea. 2. These atypical corpora persisted from 5 to 8 days, concurrently with vaginal diestrus. They then became white and a second vaginal estrus occurred, unaccompanied by red corpora. Transplants showed considerable growth between the first and second estrus. 3. Similar transplants in ovariectomized virgin females developed vesicular follicles and corpora lutea from the 10th day onwards, with more or less normal estrus cycles. Corpora were typically white. Growth of transplants was moderate but continuous. 4. It is suggested that red corpora lutea indicate the action of LTH; and that pituitary release of LH, but not of FSH, is inhibited over most of the lactation interval.