Abstract
Progesterone (300-400 microM) and oestradiol (25-200 microM) induce a prompt rise in the cytosolic free Ca2+ concentration (free Ca) in single rat hepatocytes, but testosterone, cortisol and dexamethasone do not. These increases are dependent on the presence of extracellular Ca2+. Both progesterone and oestradiol block phenylephrine-induced free Ca oscillations. These data suggest a certain specificity of the response of free Ca to steroids and may explain some of the non-genomic effects of these steroids on hepatocytes.