Phospholipid-induced human platelet activation: effects of calcium channel blockers and calcium chelators.
Human platelet activation (aggregation, [14C]-5HT release and TxB2 production) induced by the phospholipids, PAF and lysophosphatidic acid (LPA) was inhibited by EGTA, TMB-8 (an intracellular calcium antagonist) and by phenylalkylamine (Class II) but not 1,4-dihydropyridine (Class I) calcium channel blockers. Primary aggregation induced by PAF was selectively inhibited by phenylalkylamine (verapamil, methoxyverapamil) calcium channel blockers. Phospholipid-induced human platelet activation depends predominantly on the influx of extracellular calcium, possibly via specific receptor-operated calcium channels.
D001692:Biological Transport; D001792:Blood Platelets / Q000378:metabolism; D002118:Calcium / Q000378:metabolism; D002121:Calcium Channel Blockers / Q000494:pharmacology*; D002614:Chelating Agents / Q000494:pharmacology*; D006801:Humans; D007473:Ion Channels; D010743:Phospholipids / Q000037:antagonists & inhibitors* / Q000378:metabolism; D010974:Platelet Aggregation / Q000187:drug effects*
D002121:Calcium Channel Blockers; D002614:Chelating Agents; D007473:Ion Channels; D010743:Phospholipids; D002118:Calcium