Oxidative stress-induced cadmium resistance in Chinese hamster V79 cells

Injections of an aqueous extract of winter cherry fruits (Physalis alkekengi) to adult female cycling rats by an intraperitoneal route resulted in the diminution of the pituitary lysyl-aminopeptidase (Lys-AP) activity by 50% and that of the basomedial hypothalamus (BMH) by 45%. Administration of daily doses of 3.75, 7.5, and 15 micrograms beta-estradiol for a period of 5-8 days to such animals increased pituitary Lys-AP activity 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 given dose of the aqueous extract for 7-8 days diminished Lys-AP inhibitory 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 enzymes of both tissues, being estrogen-induced proteins, are inhibited by the estrogen antagonistic principle of the winter cherry aqueous extract. It is further suggested that BMH Lys-AP activity may be used as an enzyme marker for the action of beta-estradiol in hypothalamus.