Effects of estradiol and progesterone on rat uterine ribonuclease inhibitor activity.

The effects of estradiol (E2) and progesterone on rat uterine RNase inhibitor activity were investigated. RNase inhibitor activity was found to be most prominent in nuclear and cytosolic fractions of the uterus. Uterine RNase inhibitor activity in the 45,000 x g cytosolic fraction was stimulated by E2 over a 6-24 hr treatment period. Progesterone did not produce a significant change in the uterine cytosolic RNase inhibitor activity during the same period.