Evidence for endogenous opioid control of vasopressin release in man

The role of endogenous opioids in the control of vasopressin secretion was studied using the pure opiate antagonist naloxone. Naloxone both reduced resting levels of vasopressin and inhibited the rise in vasopressin induced by an orthostatic stimulus. These results suggest that endogenous opioids are important as a tonic stimulus to vasopressin release in man.