Role of central vasopressin in cardiovascular regulation.

Using techniques of intracerebroventricular administration of vasopressin, microinjection of vasopressin into specific brain nuclei, electrical stimulation, and ablation of specific nuclei, we found that vasopressin, through an effect on central neural structures, increases mean arterial pressure and heart rate via an increase in sympathetic outflow and that deoxycorticosterone acetate (DOCA)-salt hypertensive rats show increased sensitivity and responsiveness to the central effects of vasopressin. Furthermore, we found that an important central target area for the cardiovascular effects of vasopressin is the pontine nucleus locus coeruleus. Ablation of the locus coeruleus markedly attenuates the cardiovascular effects of vasopressin as well as the development of DOCA-salt hypertension. Taken together, our results suggest a link between vasopressin, the locus coeruleus, and the sympathetic nervous system in normal cardiovascular regulation as well as in the pathogenesis of DOCA-salt hypertension. Our studies support the hypothesis that vasopressin modifies sympathetic drive through an action on central neural target areas, such as the locus coeruleus controlling sympathetic outflow. Our data further suggests that vasopressin may participate in the pathogenesis of DOCA-salt hypertension by inducing stimulation of the sympathetic nervous system at the region of the locus coeruleus in this model.