The role of substrate in the hypoxic response of the pulmonary artery.

Present data suggest that acute hypoxia has, indeed, a [See Table in the PDF File] direct effect on the isolated pulmonary vascular smooth muscle preparation. Substrate dependency of pulmonary artery during acute hypoxia reveals an important link between the production of energy and smooth muscle tone. The maintenance of anaerobic glycolysis appears to be necessary for the preservation of resting tone of pulmonary artery. In spite of tissue calcium accumulation during acute anoxia, pulmonary artery in substraterich medium does not increase its tone. The initial tension appears to be the important factor affecting the hypoxic response of isolated pulmonary artery.