[Effect of consecutive administration of obsidan and novodrin on pulmonary circulation in anesthesized dogs]

It was established in experiments on mongrel anesthesized dogs that the beta-blocking agent obsidan (propranolol) in a dose of 0.5-1.0 mg/kg causes an increase in total pulmonary and pulmono-arteriole resistance, which correlates with the decrease in volume blood flow in the pulmonary arteries. The pressure in the pulmonary artery and the left atrium does not change substantially. Injection of 0.25-0.5 mg of novodrin increases the volume blood flow, causes no effect on pressure in the left atrium, and reduces total pulmonary resistance. The changes occurring in pulmonary circulation under the effect of beta-adrenergic agents depend on their primary action on cardiac activity whereas the increase in total pulmonary and pulmono-arteriole resistance depends on the secondary spasm of the pulmonary vessels.