Chronic constriction of the external and internal carotid arteries in dogs: its effect on the blood pressure.

NEUROGENIC hypertension can be produced in dogs by denervation of the carotid sinus and disruption of the vago-aortic nerves. This procedure usually results in severe hypertension, the hemodynamics of which were studied by several investigators.' Chronic disruption of the carotid sinus nerves alone, was thought not to effect the blood pressure. This Avas attributed to sufficient buffer action of the remaining baroreceptors. Wakerlin and co-workers reported that bilateral constriction of the carotid sinus in dogs by plastic clamps resulted in moderate hypertension. Although the authors showed that the carotid sinus nerves were inadvertently disrupted by the clamp in most of these animals, they preferred to explain the mechanism of hypertension in their experiments by a change in cerebral hemodynamics rather than by altered carotid sinus function."' To clarify the problem of carotid sinus participation in this type of hypertension, experiments were devised in which cerebral hemodynamics were altered by constriction of the external and internal carotid arteries with the carotid sinus nerves left intact at first. Denervation of the carotid sinus was performed several months later to elucidate whether hypertension develops before or after disruption of the carotid sinus nerves.