[Radioimmunoassay of arginine vasopressin in unextracted random urine: clinical application for discrimination of diabetes insipidus].

The concentration of arginine vasopressin in unextracted random urine was directly measured by radioimmunoassay. The urinary AVP value (Vm) measured by RIA, their AVP value (Vc) revised by urinary creatinine and their AVP value (Vc/op) revised by urinary creatinine and urinary osmotic pressure were applied for discriminate diagnosis of diabetes insipidus (DI). In children with central DI, Vm was significantly lower then that of normal subjects and the distribution of Vm was different from that of normal subjects. In children with renal DI, the distribution of Vc/op was different from that of normal subjects. In conclusion the children with central DI and renal DI can be discriminated from the normal children in comparison with Vm and Vc/op.