Abstract
Corpus luteum weight and function were studied in mature ewes following an intramuscular injection of 500 or 750 μg. of 17β estradiol on each of days 11 and 12 of the estrous cycle (first day of estrus=day 0 of the cycle). Control and treated ewes were autopsied on days 13 or 15 of the same cycle. Estradiol reduced luteal weight and luteal progesterone content and concentration significantly by day 13, and caused even greater regression of corpora lutea by day 15. In ewes hysterectomized on day 5 of the cycle, estradiol injected on days 11 and 12 failed to cause regression of corpora lutea, suggesting involvement of the uterus in the effect of estradiol on the corpus luteum. Copyright © 1969. American Society of Animal Science. Copyright 1969 by American Society of Animal Science