sr-144528 and Arrhythmias--Cardiac

We have found that intravenous administration of cannabinoid receptor (CB) agonist HU-210 (0.05 mg/kg), increases cardiac resistance against arrhythmogenic effect of epinephrine, aconitine, coronary artery occlusion and reperfusion in rats. Pretreatment with CB2-receptor antagonist, SR144528 (1 mg/kg), completely abolished the antiarrhythmic effect of HU-210. However this effect of HU-210 was not attenuated by pretreatment with CB1-receptor antagonist, SR141716A (3 mg/kg). We also found that HU-210 (0.05 mg/kg) decreased the relationship between infarction size and area of ischemia. It is concluded that CB2 receptor stimulation promotes an increase in the cardiac resistance against arrhythmogenic influences and probably increases myocardial tolerance of both ischemic and reperfusion damages in rats.

Topics: Aconitine; Animals; Anti-Arrhythmia Agents; Arrhythmias, Cardiac; Arterial Occlusive Diseases; Camphanes; Cannabinoids; Coronary Artery Disease; Dronabinol; Epinephrine; Male; Myocardial Infarction; Myocardial Reperfusion Injury; Piperidines; Pyrazoles; Rats; Rats, Wistar; Receptor, Cannabinoid, CB2; Receptors, Cannabinoid; Receptors, Drug; Rimonabant

Intravenous injection of 10 mg/kg anandamide reduces the incidence and duration of epinephrine-induced arrhythmias in rats. SR141716A and SR144528, antagonists of cannabinoid receptor I and II did not abolish the antiarrhythmic effect of anandamide. These data suggest that the antiarrhythmic effect of anandamide is nonspecific or mediated via unknown cannabinoid receptors, but not associated with activation of cannabinoid receptors I and II.

Topics: Animals; Arachidonic Acids; Arrhythmias, Cardiac; Camphanes; Electrocardiography; Endocannabinoids; Epinephrine; Heart; Piperidines; Polyunsaturated Alkamides; Pyrazoles; Rats; Rats, Wistar; Receptor, Cannabinoid, CB2; Receptors, Cannabinoid; Receptors, Drug; Rimonabant