Cardiovascular research
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Cardiovascular research · Jun 1993
Oxygen radical scavenging agents as adjuvant therapy with tissue plasminogen activator in a canine model of coronary thrombolysis.
Early thrombolysis can reduce infarct size and enhance the long term recovery of contractile function after acute myocardial infarction. These benefits of early reperfusion may be confounded, however, by platelet mediated reocclusion after initial lysis, and "reperfusion injury" mediated by oxygen derived free radicals. Superoxide dismutase (SOD)--as well as its action as a potent free radical scavenging agent--inhibits platelet aggregation in vitro. Thus our primary objectives were to determine whether SOD+catalase, given as adjuvant therapy with recombinant human tissue plasminogen activator, could inhibit platelet aggregation and thereby reduce the time to lysis and maintain arterial patency. Whether SOD+catalase enhanced myocardial salvage or improved acute recovery of contractile function in the setting of thrombosis/thrombolysis was also assessed. ⋯ Although SOD+catalase acutely attenuated platelet aggregation and slightly accelerated lysis, these agents failed to limit platelet mediated rethrombosis. Furthermore, SOD+catalase did not enhance myocardial salvage and did not improve acute recovery of contractile function after thrombosis/thrombolysis. Thus SOD+catalase given as adjuvant therapy with tissue plasminogen activator did not have a substantial beneficial effect on either the efficacy of thrombolysis or on "reperfusion injury" in this canine model.