PREVENTION BY AN INHIBITOR OF THE L-ARGININE-NITRIC OXIDE PATHWAY OF THE ANTIARRHYTHMIC EFFECTS OF BRADYKININ IN ANESTHETIZED DOGS

The intracoronary administration of bradykinin (25 ng kg-1 min-1) mark edly reduces the severity of arrhythmias that occur during a 25 min oc clusion of the left anterior descending coronary artery in chloralose, urethane anaesthetized dogs. This protection was abolished by the pri or administration, by the same route, of N(G)-nitro-L-arginine methyl ester (L-NAME); an inhibitor of the L-arginine-nitric oxide pathway. T he protective effect of bradykinin on reperfusion-induced VF was not a ffected by L-NAME. These results strongly suggest that the antiarrhyth mic effect of bradykinin in this model is mediated by nitric oxide rel ease. It also supports the concept that bradykinin might be a 'primary mediator' of the protective antiarrhythmic effects of ischaemic preco nditioning.