MODULATION OF THE PITUITARY AND BASOMEDIAL HYPOTHALAMIC LYSYL-AMINOPEPTIDASE ACTIVITIES BY BETA-ESTRADIOL AND OR AN AQUEOUS EXTRACT OF PHYSALIS-ALKEKENGI FRUITS/

Injections of an aqueous extract of winter cherry fruits (Physalis alk ekengi) to adult female cycling rats by an intraperitoneal route resul ted in the diminution of the pituitary lysyl-aminopeptidase (Lys-AP) a ctivity by 50% and that of the basomedial hypothalamus (BMH) by 45%. A dministration of daily doses of 3.75, 7.5, and 15 mu g beta-estradiol for a period of 5-8 days to such animals increased pituitary Lys-AP ac tivity from 31% to 61.5% and that of BMH from 20% to 87%, respectively . Administration of the same doses of beta-estradiol along with a give n dose of the aqueous extract for 7-8 days diminished Lys-AP inhibitor y effect of the extract in both the pituitary and BMH and eventually, at the highest dose of beta-estradiol, increased the pituitary enzyme activity by 9% and that of BMH by 5%. It is concluded that Lys-AP enzy mes of both tissues, being estrogen-induced. proteins, are inhibited D y the estrogen antagonistic principle of the winter cherry aqueous ext ract. It is further suggested that BMH Lys-AP activity may be used as an enzyme marker for the action of beta-estradiol in hypothalamus.