Control by the Superior Cervical Ganglion of the State of Contraction and Pulsatile Expansion of the Carotid Sinus Arterial Wall

The state of contraction and resistance to stretch of the arterial wall of the carotid sinus modulates sensitivity of pressoreceptors to intra-arterial pressure. Experiments show that electric stimulation of efferent sympathetic pathways to the carotid sinus leads to blood pressure fall and decrease of the carotid sinus hypertensive reflex. This effect can be prevented by local application of Regitine to the carotid sinus. These experiments suggest that the state of contraction and resistance to stretch of the barosensitive arterial walls is controlled by sympathetic innervation through local release of norepinephrine and/or epinephrine. Disturbances of this innervation could have a role in development of abnormal relaxation and decreased pulsatile expansion of the barosensitive arterial walls, and, thus, in the pathogenesis of hypertension.