The effects of dopamine on prostaglandin E1-elicited electrophysiological changes in a neuronal somatic cell hybrid.

PGE1 elicited a slow, dose-dependent membrane depolarization with an increase in membrane conductance in the somatic cell hybrid TCX11. The ED50 was 1-2 X 10(-8) M with maximal responses at 1-5 X 10(-7) M. Dopamine (DA) reversed the effect of PGE1 and caused the membrane potential and resistance to return to control levels. Chronic exposure of cells (measured in minutes) to DA alone would not cause this hyperpolarization. 5-HT was also tested and failed to consistently reverse the PGE1 effects. Chlorpromazine antagonized the effects of DA on the PGE1 response. The electrophysiological results reported here using TCX11 cells are discussed in light of previously reported biochemical results describing interactions of PGE1 and DA, and the electrophysiological effects of DA alone.