title: Increased renal sensitivity to vasopressin in two patients with essential hypernatremia.
abstract: Patients with essential hypernatremia maintain urinary concentrating ability despite plasma hyperosmolality and low plasma vasopressin concentrations. We investigated renal sensitivity to ultralow dose vasopressin infusions in two patients with a syndrome of hypodipsia, hypernatremia with selective osmoreceptor dysfunction, early puberty, and aggressive behavior. The patients were water loaded until a hypotonic diuresis was established. Vasopressin was infused in stepwise increments from 0.4-12 fmol/kg X min. Both patients had increased renal sensitivity to vasopressin, achieving negative free water clearance at infusion rates of 0.4 and 4 fmol/kg X min (normal greater than or equal to 6). Treatment for 3 months with 1-desamino-8-D-arginine vasopressin (DDAVP) led to an improvement in behavior and the reporting, for the first time, of a sensation of thirst. After DDAVP therapy both patients had a reduction of their renal sensitivity to infused vasopressin. We conclude that untreated patients with essential hypernatremia have increased renal sensitivity to vasopressin which is reduced by DDAVP administration.
mesh_terms: D000293:Adolescent; D000328:Adult; D003894:Deamino Arginine Vasopressin / Q000627:therapeutic use*; D004305:Dose-Response Relationship, Drug; D004359:Drug Therapy, Combination; D006801:Humans; D006955:Hypernatremia / Q000188:drug therapy* / Q000378:metabolism; D007668:Kidney / Q000187:drug effects*; D008297:Male; D009994:Osmolar Concentration; D014667:Vasopressins / Q000008:administration & dosage* / Q000097:blood / Q000652:urine; D014882:Water-Electrolyte Balance
chemical_list: D014667:Vasopressins; D003894:Deamino Arginine Vasopressin