EFFECT OF OSMOTIC STIMULI ON THE CONCENTRATION OF VASOPRESSIN IN JUGULAR AND PERIPHERAL VENOUS PLASMA

Abstract

Publisher Summary The relation between the rate of secretion of vasopressin and the osmolality of the body fluids is a basic element of the extracellular fluid homeostasis. The chapter presents experiments conducted on conscious, euhydrated dogs, which evaluate the effect of short, bilateral, and intracarotid infusions of hypertonic saline on the concentrations of vasopressin in jugular and systemic plasma. The results show that (1) infusions of hypertonic saline bilaterally into the common carotid arteries are associated with an increase in the concentration of vasopressin in plasma, (2) intravenous administration of identical, hypertonic solutions are ineffective - or at least much less effective - in eliciting the release of vasopressin, and (3) the difference between the concentration of vasopressin in jugular venous plasma and the concentration in venous plasma from a hind leg is small and statistically demonstrable only in some of the animals. The mechanisms responsible for the control of the secretion of vasopressin normally maintain a delicate balance sensitive to stimuli, which are part of homeostatic systems and to perturbations, which a priori would have appeared less likely to influence the secretion of this hormone..