ROLE AND SITE OF ESTROGEN ACTION IN FOLLICULAR ATRESIA

Subsequent to an initial understanding that estrogen was only stimulat ory to folliculogenesis, lye have come full circle to the present reco gnition that many actions of estrogen are inhibitory to follicular fun ction. The development of this interpretation has frequently been asso ciated with the controversial issue of the likely site of estrogen act ion, especially in primates, where much of the evidence has been amass ed. The accumulated findings in a variety of species seem to demonstra te clearly that at least part of the atretogenic effect of estrogen is exerted directly on the ovary, apparently by interaction with the nuc lear estrogen receptor Recent observations include identification of m essenger RNAs for the estrogen receptor and for creatine kinase in the macaque ovary, and a current focus is to localize messages within spe cific compartments of the ovary.