Central and cardiac histamine receptors involvement in the anti-arrhythmic effect of cimetidine
Abstract
Intracerebroventricular injection (icv) of cimetidine 37.5μg delayed and icv histamine diphosphate 20 μg shortened the onset o fbentricular extrasystole (VE) and ventricular tachycardia (VT) produced by icv aconitine 15 μg/μl in the anesthetized rats,whereas icv diphenhydramine 37.5μg exerted no influence on these arrhythmias.
In the spinal rats, cimetidine 120 mg/kg iv significantly elevated the dose of aconitine (2 μg/min iv) required to induce VE, VT and ventricular fibrillation(VF), but iv infusion of histamine diphosphate (20 mg/kg/h) did not. Therefore these results suggested that cimetidine antagonized aconitine-arrhythmia through the central H2-receptors and peripheral mechanism was independent of the cardiac histamine receptor.
Keywords:
In the spinal rats, cimetidine 120 mg/kg iv significantly elevated the dose of aconitine (2 μg/min iv) required to induce VE, VT and ventricular fibrillation(VF), but iv infusion of histamine diphosphate (20 mg/kg/h) did not. Therefore these results suggested that cimetidine antagonized aconitine-arrhythmia through the central H2-receptors and peripheral mechanism was independent of the cardiac histamine receptor.