Effect of estradiol on corpus luteum function in pregnant hamster

Abstract

It was found that parturition in the hamster is associated with low circulating and luteal progesterone,low tissue-bound LH in carpus luteura (CL), high esterified cholesterol in CL, high circulating LH and peak levels of estrogen in serum, CL and the non-luteal ovarian tissue. The high concentrations of estrogen suggested a role for this steroid hormone in the regulation of corpus luteum function. Hence the effect of estradiol on the in vivo and in vitro functionality of corpus luteum was studied. It was found that administration of estradiol to pregnant hamsters resulted in a drastic reduction of progesterone levels in the serum. A direct inhibitory effect of estradiol on the progesterone production by the corpus luteum in vitro was observed. This inhibition of progesterone production occurred between 30 and 45. LH responsiveness of corpus luteum diminished considerably in presence of estradiol.