RESUMEN
BACKGROUND: Dopamine is an inotrope effective in the short term treatment of acute heart failure - including that caused by coronary artery disease. Catecholamines however can potentiate platelet activation and pre-dispose to coronary thrombosis. AIMS: Dopamine was studied for effect on agonist induced human platelet Ca mobilization, human platelet GP iib iiia receptor activation and acute coronary thrombosis in dogs. Calcium sensitive indo-1, fluorescent immunostaining and flow cytometry were used for platelet studies while coronary thrombosis was induced in anesthetized dogs via endothelial damage, arterial wall injury and critical stenosis. RESULTS: Dopamine 10 and 10 M had no effect on the amplitude of the platelet Ca signal evoked by thrombin 0.1 U/mL. Likewise, dopamine 10 M had no effect on GP IIb IIIa activation evoked by ADP 10 M and by thrombin 0.1 U/mL. In dogs, intravenous dopamine 8 ug/Kg/min had no effect on repetitive cycles of acute coronary thrombus formation. In positive control studies, epinephrine increased platelet responsiveness and accelerated canine coronary thrombosis. CONCLUSION: Clinically relevant concentrations of dopamine did not amplify agonist induced human platelet Ca activation, GPiib iiia expression or experimental canine coronary thrombosis--providing a degree of reassurance concerning this versatile inotrope.