title: Rat platelet aggregation by ATP. Aggregometrical and ultrastructural comparison with aggregations induced by ADP and collagen.
abstract: This paper describes the aggregation of rat platelets by adenosine triphosphate (ATP). The aggregometry of ATP-induced aggregation and the ultrastructure of ATP-aggregated platelets were compared and contrasted with those of adenosine diphosphate (ADP)-treated and collagen-treated samples. Human platelets were also studied alongside with rat specimens. Several lines of evidence indicate that the ATP-induced aggregation of rat platelet-rich plasma (PRP) is not a result of contaminating ADP in the ATP preparation. ATP did not cause aggregation of human platelets; it inhibited ADP- and collagen-induced human platelet aggregation. ATP pretreated with a creatine phosphate/creatine phosphokinase system caused similar rat platelet aggregation as did ATP not treated with this system. The aggregometry of ATP-induced aggregation of rat PRP was similar to that of collagen-induced aggregation but markedly different from that of ADP-induced aggregation. However, the nature of ATP-induced aggregation was similar to that induced by ADP. Both ATP- and ADP-induced rat platelet aggregations were not affected by adenosine, adenosine monophosphate, or acetylsalicylic acid. The ultrastructure of ATP-aggregated platelets was similar to that of ADP-aggregated ones. It appears that either platelets of rats possess specific ATP receptors or the rat plasma contains a material, lacking or insufficiently present in human plasma, that converts ATP to ADP in a fashion similar to the release of ADP from platelet storage granules.
mesh_terms: D000241:Adenosine / Q000494:pharmacology; D000244:Adenosine Diphosphate / Q000494:pharmacology; D000249:Adenosine Monophosphate / Q000494:pharmacology; D000255:Adenosine Triphosphate / Q000494:pharmacology*; D000818:Animals; D001081:Apyrase / Q000494:pharmacology; D001241:Aspirin / Q000494:pharmacology; D001792:Blood Platelets / Q000648:ultrastructure*; D003094:Collagen / Q000494:pharmacology; D005260:Female; D006801:Humans; D008297:Male; D010974:Platelet Aggregation / Q000187:drug effects*; D051381:Rats
chemical_list: D000249:Adenosine Monophosphate; D000244:Adenosine Diphosphate; D000255:Adenosine Triphosphate; D003094:Collagen; D001081:Apyrase; D000241:Adenosine; D001241:Aspirin