Evidence for the involvement of Na+/Ca2+ exchange in the stimulation of inositol phospholipid hydrolysis by sodium channel activation and depolarization.
Amiloride, an inhibitor of the Na+/Ca2+ exchanger, blocked the hydrolysis of inositol phospholipids in mouse cerebrocortical slices induced by the sodium channel activator veratridine, by KCl, or by the sodium ionophore monensin; there was no inhibition by A 23187, a Ca2+ ionophore, or by serotonin. It is concluded that agents that increase intracellular Na2+ stimulate inositide hydrolysis by an indirect effect via Na+/Ca2+ exchange.
Benuck
M
M
Center for Neurochemistry, Nathan S. Kline Institute for Psychiatric Research, Ward's Island, New York, NY 10035.
Reith
M E
ME
Lajtha
A
A
D000584:Amiloride / Q000494:pharmacology; D000818:Animals; D000001:Calcimycin / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism*; D002217:Carbachol / Q000494:pharmacology; D006868:Hydrolysis; D007295:Inositol Phosphates / Q000378:metabolism*; D007474:Ion Exchange; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008985:Monensin / Q000494:pharmacology; D010042:Ouabain / Q000494:pharmacology; D012964:Sodium / Q000378:metabolism*; D015222:Sodium Channels / Q000187:drug effects / Q000378:metabolism*; D013403:Sugar Phosphates / Q000378:metabolism*; D013779:Tetrodotoxin / Q000494:pharmacology
D007295:Inositol Phosphates; D015222:Sodium Channels; D013403:Sugar Phosphates; D000001:Calcimycin; D013779:Tetrodotoxin; D010042:Ouabain; D000584:Amiloride; D002217:Carbachol; D008985:Monensin; D012964:Sodium; D002118:Calcium