[Catecholamines in the myocardium of growing rats after pharmacological sympathectomy]

Examination of the myocardium of 7-, 30-day and 3--5-month-old rats has shown that the content of noradrenaline and adrenaline increased with age. The sympatholytics, reserpine and ornid diminished more markedly the content of catecholamines in the myocardium of 7- and 30-day-old animals. Dopegyt produced a greater catecholamine-reducing effect in 3--5-month-old animals. It is inferred that in the early postnatal ontogenesis, the myocardial response to the sympatholytics is determined by age-associated features of adrenergic control and metabolism.