Age-related protective role of parasympathetic nervous system against hypercalcaemia-induced ventricular arrhythmias in the rat.
Time of appearance of extrasystoles, ventricular fibrillation, and cardiac arrest were monitored in urethane-anaesthetized rats of different ages following CaCl2 infusion. Ca++ required to produce ventricular arrhythmias was significantly higher in younger than in older animals. Bilateral vagotomy or atropine treatment significantly reduced Ca++ requirements for production of arrhythmias in younger but not in older animals. These findings support the hypothesis of vagally mediated age-related antagonism toward Ca++-induced ventricular arrhythmias. This suggests that young subjects are less prone to develop ventricular rhythm disturbances as a result of hypercalcaemic states.
D000367:Age Factors; D000818:Animals; D001145:Arrhythmias, Cardiac / Q000209:etiology*; D001285:Atropine / Q000494:pharmacology; D001919:Bradycardia / Q000209:etiology; D005117:Cardiac Complexes, Premature / Q000209:etiology; D006323:Heart Arrest / Q000209:etiology; D006934:Hypercalcemia / Q000150:complications*; D008297:Male; D010275:Parasympathetic Nervous System / Q000502:physiology*; D051381:Rats; D013997:Time Factors; D014628:Vagotomy; D014693:Ventricular Fibrillation / Q000209:etiology
D001285:Atropine