Human Prolactin Receptor and Dopamine Actions in Feminizing Adrenal Neoplastic Cells

Estrogen production by feminizing adrenal neoplastic cells (Fang-8 cells) in culture was stimulated by human prolactin (hPRL). The existence of hPRL receptor in the cells was demonstrated. The stimulatory effect of hPRL was abolished by dopamine and CB-154 (2-bromo-α-ergocriptine), since CB-154, at 60 μg/dish, inhibited cell growth and estrogen production in the absence of hPRL and since dopamine may involve different mechanisms of action. The action of CB-154 was blocked by propranolol, not by phenoxybenzamine or pimozide. Since we could not demonstrate adrenergic or dopaminergic receptor in Fang-8 cells, the interaction between CB-154 and propranolol may not be explained by a pharmacological beta-adrenergic mechanism.