title: Experimental comparison of the efficacy of various agents on the enhancement of myocardial protection.
abstract: Experimental studies were carried out to compare the efficacy of various agents such as calcium antagonists, phosphodiesterase inhibitors, adrenocorticosteroids, coenzyme Q10 (CoQ10), insulin, beta-blocking agent and reduced glutathion (GSH) on the enhancement of myocardial protection. Eighty-five isolated rabbit hearts were subjected to 2 hours of cardioplegic arrest, and maximum developed tension, heart rate, coronary blood flow and coronary arteriovenous oxygen difference following reperfusion were compared between groups pretreated with different agents. The greatest value of maximum developed tension was obtained in the verapamil-treated group (0.2-0.5 mg/kg), followed by dilazep (1 mg/kg), pentoxifylline (30 mg/kg) and CoQ10 (10 mg/kg) treated groups. The time required for the recoveries of spontaneous beating (normal sinus rhythm) on reperfusion was shortest (44 +/- 8 sec) in the group treated with a cardioplegic solution containing a low concentration of betamethasone (0.03-0.05 mg/ml), but the so-called stone hearts and cardiac arrhythmias were most frequently seen in this group. On the contrary, in the group pretreated with calcium antagonists, the time required for the restoration of sinus rhythm was much longer (88-180 sec). Hence, the shortest recovery time was not necessarily associated with a better recovery of myocardial function.
mesh_terms: D000319:Adrenergic beta-Antagonists / Q000494:pharmacology*; D000818:Animals; D002121:Calcium Channel Blockers / Q000494:pharmacology*; D003067:Coenzymes; D003326:Coronary Circulation / Q000187:drug effects; D006324:Heart Arrest, Induced; D006339:Heart Rate / Q000187:drug effects; D066298:In Vitro Techniques; D007328:Insulin / Q000494:pharmacology; D009206:Myocardium / Q000378:metabolism; D010101:Oxygen Consumption / Q000187:drug effects; D010477:Perfusion; D011817:Rabbits; D014451:Ubiquinone / Q000031:analogs & derivatives / Q000494:pharmacology
chemical_list: D000319:Adrenergic beta-Antagonists; D002121:Calcium Channel Blockers; D003067:Coenzymes; D007328:Insulin; D014451:Ubiquinone; C024989:coenzyme Q10