Cardiovascular response to glucagon in hypovolemic dogs

Glucagon in a dose of 50 mug/kg body weight was studied for its cardiovascular effects in hypovolemic dogs in which coronary blood flow was reduced to an average 40% of its control value and cardiac depression was evident. Myocardial contractility, as judged mainly by dP/dt and acceleration of aortic blood flow, was brought to a normal level for a short time. Systemic and coronary vascular resistances were markedly reduced. These effects were similar in normovolemic dogs. The inotropic, chronotropic, and peripheral vascular effects of glucagon can be evoked also in hypovolemic dogs in which coronary blood flow is less than normal and myocardial metabolism is impaired.