Water immersion (WI) induced alterations of plasma vasopressin (AVP) levels in patients with noninflammatory acute renal failure (NARF) and in patients with chronic renal failure (CRF).

Water immersion (WI) induced alterations of plasma vasopressin (AVP), plasma osmolality, plasma volume (PV) and plasma sodium and potassium concentration were examined in 12 patients with noninflammatory acute renal failure (NARF) at the anuric/oliguric phase, 20 patients with chronic renal failure (CRF) and 15 healthy persons. In all examined groups a significant increase of PV and decrease of plasma osmolality and AVP after WI was observed. In patients with NARF the increase of PV was significantly greater than in CRF and in healthy persons. In patients with NARF a significantly greater decrease of plasma sodium concentration after WI was also noted than in patients with CRF and in healthy persons. Only in healthy persons, but not in patients with acute or chronic renal failure a significant correlation between PV or decrease of plasma osmolality and WI induced decrease of plasma AVP level was stated. We conclude that patients with NARF and CRF are characterized by an inappropriate volumetric and osmotic regulation of AVP secretion.