The effect of the cold pressor test on vasopressin secretion in man.
Stress has been thought to induce the release of arginine vasopressin (AVP). We evaluated this claim by studying the effects of a modified cold pressor test on plasma AVP, plasma cortisol, blood pressure, pulse rate, and a number of variables known to affect AVP secretion. In a cross-over study design, test and control values were obtained in seven male subjects. The pressor test was found to induce painful stress as evidenced by subjective reports and the objective findings of increased mean arterial pressure (13.9 +/- 3.1 mm Hg; p less than 0.004), pulse rate (9.2 +/- 2.8 beats/min; p less than 0.02), and plasma cortisol (3.5 +/- 0.8 micrograms/dl; p less than 0.005). In contrast, there were no significant changes in plasma AVP that could be attributed to the cold pressor test. There also were no changes in plasma osmolality, measured plasma solutes, hematocrit or body temperature. An unexpected finding was a premonitory drop in plasma AVP occurring just prior to the pressor test (2.5 +/- 2.0 pg/ml; p less than 0.04) and at the comparable time point in the control study (3.1 +/- 1.2 pg/ml; p less than 0.001). There were no changes in any of the other measured variables which could account for this drop. We conclude that the cold pressor test is not a stimulus to AVP release and that anticipation of stress may inhibit secretion of this hormone.