[Effect of dihydroergotoxin on myocardial capacitance vessels]

Experiments were performed on the isolated cat hearts, coronary vessels being perfused with donor cat blood. Dihydroergotoxin injected into the coronary vessels (0.5 mg) decreased their vascular capacity. This resulted from active constriction of the coronary vessels, since it was seen in experiments with the heart arrested with strophathin as well. Active constriction of the coronary veins under the action of dihydroergotoxin was not related to its specific properties as an alpha-blocking drug, and resulted from a direct action of the drug on the smooth muscle of the coronary veins.