title: Movement of sodium into human platelets.
abstract: Addition of ADP induces platelets in plasma to undergo shape change from a disc to a spiny sphere and to develope adhesiveness, i.e. to aggregate. The aggregation of human platelets by ADP is associated with a net uptake of Na+. The present experiments demonstrate that the induction of shape change by ADP in acidified or EGTA-treated plasma conditions which inhibit aggregation, is also associated with a movement of Na+ into platelets. When ADP-induced platelet shape change and aggregation is inhibited by prostaglandin E1 Na+ uptake is also blocked. Platelets aggregated by epinephrine do not take up Na+. In a manner analogous to the effect of ADP, polylysine also induces Na+ uptake during aggregation. Vasopressin, in a manner analogous to epinephrine, induces aggregation without Na+ uptake. The increase in platelet Na+ resulting from ouabain inhibition of Na+ efflux induces an increase in the aggregation response to ADP and to epinephrine.
mesh_terms: D001692:Biological Transport / Q000187:drug effects; D001792:Blood Platelets / Q000187:drug effects / Q000378:metabolism*; D004837:Epinephrine / Q000494:pharmacology; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D010042:Ouabain / Q000494:pharmacology; D010974:Platelet Aggregation / Q000187:drug effects*; D011458:Prostaglandins E / Q000494:pharmacology; D012964:Sodium / Q000097:blood*
chemical_list: D011458:Prostaglandins E; D010042:Ouabain; D012964:Sodium; D004837:Epinephrine