Vasopressin and cortisol levels in response to glycine infusion

The plasma vasopressin and serum cortisol concentrations were recorded in 7 healthy volunteers receiving an intravenous infusion of 1 l of isosmotic (2.2%) glycine solution during 20 min. The infusion elicited a significant increase in the plasma vasopressin level by a mean of 60% (SEM 13) above baseline level. The serum cortisol level increased only in the patient who developed signs of glycine toxicity. These results suggest that a glycine solution has water-retaining properties by stimulating the vasopressin secretion but usually not by increasing cortisol secretion.