Adrenergic mechanisms in cardiac ischemic responses and in the action of antianginal drugs.

The cardiovascular changes (blood pressure and electrocardiograms) following lateral hypothalamic stimulation were studied in anesthetized rhesus monkeys. It was observed that central stimulation can induce striking adrenergic cardiovascular changes, culminating in demonstrable post-mortem myocardial necrosis. In both normal and coronary-ligated anesthetized open-chest dogs, hypothalamic: stimulation leads to coronary vasodilatation followed by vasoconstriction, associated with increased pressor responses and heart contractions, and arrhythmias; prior nitroglycerin and iproveratril administrations reduce: or prevent these changes. In coronary-ligated dogs both agents antagonize post-occlusion arrhythmias and the deleterious effects of adrenergic excitation (coronary vasoconstriction and arrhythmias) induced by noradrenaline and adrenaline. [...