Cardiotoxin from Naja naja atra snake venom: a potentiator of platelet aggregation.
Cardiotoxin, isolated from Naja naja atra snake venom, potentiates platelet aggregation induced by ADP, thrombin, collagen and venom phospholipase A2. The malondialdehyde formation caused by ADP, thrombin and venom phospholipase A2 were also increased in the presence of cardiotoxin. Both potentiation of aggregation and increase in malondialdehyde were blocked by indomethacin or Ca2+ (5 mM or 0.05 mM). Cardiotoxin did not potentiate thrombin-induced aggregation of p-bromophenacyl bromide-modified platelets. Thromboxane B2 formation induced by thrombin or collagen was also increased by cardiotoxin, while that by arachidonate was not affected. As a membrane-active polypeptide, cardiotoxin might augment the Ca2+-flux during the activation of the platelet membrane by aggregation inducers and then increase the activation of endogenous phospholipase A2.
D000244:Adenosine Diphosphate / Q000494:pharmacology; D000818:Animals; D001792:Blood Platelets / Q000378:metabolism; D002118:Calcium / Q000494:pharmacology; D004179:Cobra Cardiotoxin Proteins / Q000494:pharmacology*; D003094:Collagen / Q000494:pharmacology; D003435:Crotalid Venoms / Q000494:pharmacology; D004546:Elapid Venoms / Q000494:pharmacology*; D066298:In Vitro Techniques; D007213:Indomethacin / Q000494:pharmacology; D008315:Malondialdehyde / Q000097:blood; D010741:Phospholipases A / Q000494:pharmacology; D054467:Phospholipases A2; D010974:Platelet Aggregation / Q000187:drug effects*; D011450:Prostaglandin Endoperoxides, Synthetic / Q000494:pharmacology; D011817:Rabbits; D013917:Thrombin / Q000494:pharmacology
D004179:Cobra Cardiotoxin Proteins; D003435:Crotalid Venoms; D004546:Elapid Venoms; D011450:Prostaglandin Endoperoxides, Synthetic; C029748:Trimeresurus venoms; D008315:Malondialdehyde; D000244:Adenosine Diphosphate; D003094:Collagen; D010741:Phospholipases A; D054467:Phospholipases A2; D013917:Thrombin; D002118:Calcium; D007213:Indomethacin