Toxic effects of hypoxia on neonatal cardiac function in the rat: alpha-adrenergic mechanisms.
Stimulation of peripheral alpha-adrenergic receptors by circulating catecholamines derived from the adrenal medulla is essential for surviving neonatal hypoxia. In 1-day-old rats, where sympathetic innervation of cardiovascular sites has not yet developed, blockade of these receptors results in failure of cardiac performance from a progressive decline in sinus rate and atrioventricular conduction deficits. These effects are absent in 8-day-old rats, where sympathetic efferent innervation has become established.
D000818:Animals; D000831:Animals, Newborn / Q000502:physiology*; D001794:Blood Pressure / Q000187:drug effects; D004562:Electrocardiography; D006321:Heart / Q000294:innervation; D006339:Heart Rate / Q000187:drug effects; D006439:Hemodynamics / Q000187:drug effects; D000860:Hypoxia / Q000503:physiopathology*; D010643:Phenoxybenzamine / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D011942:Receptors, Adrenergic, alpha / Q000502:physiology*
D011942:Receptors, Adrenergic, alpha; D010643:Phenoxybenzamine