Estrogen Metabolism in Subcellular Preparations and Tissue Cultures of Syrian Hamster Liver and Kidney

Abstract

Estrogen metabolism was evaluated in both kidney and liver tissues from Syrian hamsters, a potential experimental model for estrogen carcinogenesis. In initial velocity studies, apparent Kms for estrogen 2- and 4-hydroxylases ranged from 2–10 µM for liver and renal microsomes. Primary kidney cell cultures and short-term kidney tissue cultures were also utilized to examine estrogen biotransformations in intact cell systems. Both estrogen 2- and 4-hydroxylase activities were detected in these cultures. Estriol, catechol estrogens, and polar metabolites were identified from microsomal incubations. Catechol estrogens were more abundant in liver microsomal incubations than in kidney microsomal incubations; the amounts of polar metabolites were larger from renal microsomes than from liver microsomes. Kidney microsomal preparations from DES-treated hamsters yielded higher quantities of polar metabolites and lower amounts of catechol estrogens than microsomes from untreated hamsters. Kidney cultures from hamsters metabolize estradiol to yield small quantities of estrone and significant amounts of polar metabolites, and small amounts of catechol estrogens were isolated. Thus, kidney cultures from Syrian hamsters are capable of metabolizing estrogens and converting any catechol estrogens formed into more polar metabolites.