Neurogenic influences on the coronary vascular response to ischemia in the awake dog

The influence of the nervous system on the response of the coronary vessels to ischemia was evaluated by observing the reactive hyperemia subsequent to a 10 sec occlusion of the left circumflex coronary artery in 19 awake dogs. Sympathectomy produced by pretreatment with 6 hydroxydopamine, chronic total surgical cardiac denervation, beta adrenergic blockade with propranolol, and alpha blockade with phentolamine did not significantly alter the reactive hyperemic response. Thus cardiac denervation did not impair the ability of the coronary vasculature to respond to a brief ischemic stimulus.