Failure of acute intravascular volume expansion to alter plasma vasopressin in the nonhuman primate, Macaca fascicularis.

Experiments were carried out in the anesthetized monkey to determine the influence of acute hypervolemia on plasma vasopressin (ADH) concentration. The administration of an isotonic-isooncotic high molecular weight dextran infusion in two steps, each in an amount equal to 15% of the estimated blood volume, produced substantial elevations of left ventricular end diastolic pressure (17.1 cm H2O); however, no consistent change in mean plasma ADH concentration or mean arterial pressure occurred. The results support the position that in the primate, arterial blood pressure rather than blood volume is the major modulator of ADH secretion when blood volume is increased isoosmotically.