Urinary Cyclic Adenosine Monophosphate Excretion in Diabetes Insipidus of Childhood Effect of Vasopressin and Chlorpropamide

Abstract

Excretion of urinary cyclic AMP (cAMP) was determined in 7 children suffering from central diabetes insipidus (CDI), 3 children suffering from nephrogenic diabetes insipidus (NDI), and 5 normal children. Excretion of cAMP was found to be depressed in both types of DI. Administration of long-acting vasopressin in physiologically effective dosage (ADH, 5.1 U per 1.7 m²) decreased the absolute rate of cAMP excretion slightly in reference and CDI children, but had no effect on NDI children. Infusion of large doses of ADH (600 mU per 1.7 m² per h) into CDI children also reduced cAMP excretion slightly, but in relation to creatinine excretion, an increase of about 30 per cent was found. This increase of the cAMP/creatinine ratio was due to a greater decrease in creatinine than in cAMP excretion. Chlorpropamide had no effect on cAMP excretion in CDI patients.

Key Words:

• Antidiuretic hormone (vasopressin)
• cyclic adenosine 3′,5′-monophosphate (cAMP)
• diabetes insipidus