Central serotonergic agents raise the repetitive extrasystole threshold of the vulnerable period of the canine ventricular myocardium.
Systemic administration of three central serotonergic agents, melatonin, 5-methoxytryptophol, and 6-chloro-2-(1-piperazinyl)-pyrazine (MK-212), produced significant increases in the threshold of the vulnerable period for repetitive electrical activity in the canine cardiac ventricle. MK-212 was effective despite bilateral vagotomy. The specific serotonin antagonist, metergoline, blocked the effect of MK-212 on the threshold. An increase in central serotonergic activity may inhibit the flow of arrhythmogenic sympathetic nerve traffic from the brain to the heart.
D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D005117:Cardiac Complexes, Premature / Q000503:physiopathology*; D004285:Dogs; D000431:Ethanol / Q000494:pharmacology; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D006352:Heart Ventricles / Q000503:physiopathology; D007211:Indoles / Q000494:pharmacology; D008297:Male; D008550:Melatonin / Q000494:pharmacology; D010879:Piperazines / Q000494:pharmacology; D011719:Pyrazines / Q000494:pharmacology; D012701:Serotonin / Q000494:pharmacology*; D013997:Time Factors; D014628:Vagotomy
D007211:Indoles; D010879:Piperazines; D011719:Pyrazines; D012701:Serotonin; D000431:Ethanol; C014896:6-chloro-2-(1-piperazinyl)pyrazine; C002465:methoxytryptophol; D008550:Melatonin