The metabolism of 4-androstene-3,17-dione by isolated rat hepatocytes. Maintenance of the sex differences in culture.

Hepatocytes from adult rats were isolated and cultivated as primary monolayers for 3 days in a medium containing only 1% homologous serum. The metabolism of 4-androstene-3,17-dione was followed in hepatocytes from male, female and hypophysectomized animals. It was found that immediately after preparation, 5alpha-reductase and 16alpha-hydroxylase activities were present in the cells in amounts comparable to those found in microsomal preparations from liver homogenates. After 3 days in culture, these enzyme activities had decreased to about half the values measured on day 0. During this time the sexual differences in steroid metabolism in the cells were stable, i.e. there was no detectable induction of 16alpha-hydroxylase in cells from female animals, and the relative sex difference in 5alpha-reductase activity persisted.