Modulation of resting membrane potential of human and rat hepatocytes by sex steroids.

The effect of sex steroids on the regulation of hepatocyte resting membrane potential (Em) was investigated. In adult rat liver snips, Em was significantly lower in males than females. In prepubertal animals no sex related difference was observed and the Em was comparable to that of adult females. Exposure of the human liver cell line, HepG2 cells, to 10 microM testosterone resulted in a significant hyperpolarization. These data indicate that the more negative Em found in male animals is specifically due to the influence of testosterone. In addition, they also suggest that sex hormone regulation of Em is maintained by HepG2 cells. This cell line may prove to be a good model for the study of liver cell function.