Effects of Dibutyryl Cyclic AMP on the Pulmonary Hemodynamics

抄録

The effects of dibutyryl cyclic AMP (D-cAMP) on the pulmonary hemodynamics were studied in dogs. D-cAMP was administered intravenously in a dose of 30 mg/kg. The measurements of the parameters were made before and 5, 10 and 20 min after the administration of the agent. D-cAMP produced an increase in cardiac output, mean pulmonary arterial pressure and its driving pressure, but pulmonary arterial diastolic pressure and mean left atrial pressure remained almost unchanged throughout the experiments. Although pulmonary vascular resistance decreased gradually, a ratio of pulmonary vascular resistance to total peripheral vascular resistance rather increased after D-cAMP. Pulmonary vascular tension and mean pulmonary intravascular pressure also tended to increase. Pulmonary vascular compliance did not change significantly. Such changes in the pulmonary hemodynamics as produced by D-cAMP seemed to be due to secondary effects on cardiac output rather than to primary pulmonary vasoconstric-tion or vasodilatation.