精神病患者における水中毒発生機序に関する研究

Abstract

The present study was designed to elucidate the mechanism of water intoxication, which occurs almost exclusively in patients with chronic psychosis. 1) Animal experiments : Twelve rabbits were given neuroleptics for eight weeks. From measurement of arginine-vasopressin (AVP) secretion response to varied osmotic stimuli, it was suggested that chronic neuroleptics administration might raise the sensitivity of AVP secretion response. 2) Clinical study : In seventeen chronic schizophrenic patients with hyponatremia and sixteen chronic schizophrenic patients without hyponatremia, the manner of AVP secretion was investigated. In both the schizophrenic groups plasma AVP was secreted even below 270 mOsm/kg osmolality. Sensitivity of AVP secretion response to osmolality was decreased in schizophrenic patients, regardless of the presence of hyponatremia. 3) From these results, it is postulated that primary low sensitivity of osmoreceptor and secondary renal hypersensitivity to AVP could cause "hypovasopressinemic antidiuresis (SIADH)", further linked with the occurrence of water intoxication in schizophrenic patients.