Dehydroepiandrosterone sulfate (DHEAS) suppresses P2X purinoceptor-coupledresponses in PC12 cells

Some steroids rapidly alter neuronal excitability through interaction with neurotransmitter-gated ion channels in addition to their well-known genomic effects via intracellular steroid receptors. Such effects were found in GA BA receptor, nicotinic receptors, yet not investigated in P2X purinoceptors . In this study, the effects of dehydroepiandrosterone sulfate on the P2 pu rinoceptor was investigated. Results show that dehydroepiandrosterone sulfa te acutely inhibits P2X purinoceptor functions in PC12 cells. Dehydroepiand rosterone sulfate suppressed ATP-induced cytosolic free calcium concentrati on ([Ca2+](i)) rise, cytosolic free sodium concentration ([Na+](i)) rise, a nd dopamine secretion in the presence of external calcium, but had no effec t on ATP-induced [Ca2+](i) rise in the absence of external calcium or on UT P-induced [Ca2+](i) rise in the absence or presence of external calcium. Ou r data show that dehydroepiandrosterone sulfate exerted its effect on P2X, but not on the P2Y purinoceptors found in PC12 cells. Estradiol and estrone have similar effects on P2X purinoceptor, but dehydroepiandrosterone and p rogesterone do not. (C) 2001 Elsevier Science Ltd. All rights reserved.