Effect of acute hypoxaemia on plasma arginine vasopressin in conscious man.

1. Acute hypoxaemia had been reported to stimulate vasopressin release in animals. 2. Hypoxaemia induced by breathing 9-3% oxygen for 15-20 min failed to produce a rise in plasma arginine vasopressin concentration in six out of eight healthy human subjects. The two subjects who developed an increase in plasma arginine vasopressin concentration had a significant rise in serum cortisol. 3. Breathing 100% nitrogen until impairment of consciousness caused no rise in plasma arginine vasopressin concentration.