Disturbance of myocardial energy liberation in experimental charcoal embolism of canine pulmonary artery.

Experimental charcoal embolism of the pulmonary artery was produced in dogs. Changes in hemodynamics, electrophysiology, and cardiac energy liberation were observed. The effects of histaminic and antihistaminic drugs on these changes were also studied. After two infusions of charcoal suspension, acute right ventricular overloading was recognized hemodynamically and electrophysiologically. Mitochondria isolated from both ventricles exhibited uncoupling of oxidative phosphorylation polarographically. These changes were enhanced with histamine injection and reduced with diphenhydramine injection. Histamine was seen to have some uncoupling effects on the heart mitochondria and a slight effect on cardiac dynamics. It is concluded that oxidative phosphorylation of the heart mitochondria was uncoupled in the acute stage of experimental pulmonary embolism, and that histamine might emphasize this change directly or indirectly or both, that is, directly affecting the myocardial cell metabolism, and indirectly aggravating myocardial hypoxia through pulmonary vasoconstrictive action.