MITOTIC ACTIVITY OF VAGINAL EPITHELIAL CELLS FOLLOWING NEONATAL INJECTIONS OF DIFFERENT DOSES OF ESTROGEN IN MICE

摘要: In C57BlackfTw mice given injections of 1 pg estradiol-170 (E) for 5 days beginning on the day birth, and killed a few after treatment, vaginal epithelium showed estrogen-dependent proliferation parakeratosis. contrast, in treated neonatally with 30 E days, exhibited estrogen-independent cornification or Two peaks occurred mitotic rate epithelial cells proximal middle vaginae pgE-treated mice, at age, respectively, while first peak was lacking distal vagina. The activity declined to control level 60 days. animals also, 2 were found 7 both vaginae. contrast although dropped once 10 it increased again 20 remained high thereafter. second age coincided active nodules appearing mice. vagina, without preceding like that observed other parts vagina following injection birth. It is well established treatment female estrogen during neonatal life induces two different types persistent parakeratosis adulthood. One type change, brought about by low doses estrogen, ascribable permanent alteration hypothalamo-hypophysial system directly related continued secretion ovarian estrogen; other, elicited due changes itself estrogenindependent (TAKASUGI, 1963; KIMURA et al., 1967a, b; MORI, 1967; KOHRMAN GREENBERG, 1968; review see TAKASUGI 1970). From changes, cancerous precancerous lesions frequently develop