DDAVP (1-desamino-8-D-arginine vasopressin) clearance rate

Utilizing a highly sensitive radioimmunoassay (RIA) for 1-desamino-8-D-arginine vasopressin (DDAVP) and a constant infusion kinetic protocol we measured DDAVP clearance rates (CR) in 6 non-pregnant ewes. Despite mean (and SEM) plasma DDAVP levels as high as 5349 (+/- 151) pg/ml, no changes in blood pressure or heart rate were observed. The CR of DDAVP was 3.6 (+/- 0.2) ml/kg X min. This CR is only 23% of the mean arginine vasopressin (AVP) CR measured in similar animals in an earlier study. The relatively decreased CR of DDAVP appears to account largely for the approximately 5-fold prolongation of antidiuresis of this synthetic derivative relative to AVP.