[Change in systemic hemodynamics under the influence of vasopressin in dogs during ontogenesis].

Experiments were conducted on dogs (18-22 days, 2-3-month-old and adult). The central hemodynamics indices were studied after intravenous administration of 0.8 U/kg of synthetic vasopressin. The pressor effect was mostly expressed in adult dogs, and bradycardia--in 18--22-days-old puppies. All dogs displayed an increase of the total peripheral resistance accompanied by reduction of the minute output. External work of the left ventricle and expenditure of the energy by the heart rose in adult dogs. As to puppies, a reduction of the cardiac output and of the external heart work was accompanied by a lesser increase of energy expenditure.