The Effects of Changes in the Rate of Infusion of Vasopressin in Anesthetized Dogs

Abstract

The dose rate of infusion of vasopressin which can be expected to provide maximal effects upon urine formation is difficult to predict in anesthetized dogs. The anesthetic agents, the state of hydration, and the osmolal excretion may all influence the effectiveness of vasopressin. The experiments demonstrate that in moderately hydrated anesthetized dogs when the rate of vasopressin infusion is changed from 0.4 to 0.04 mU/kg min⁻¹ there is a transient dilution of the urine. The lower dose of vasopressin is four times that which completely inhibits water diuresis in conscious dogs and is larger than the dose of 0.025 mU/kg min⁻¹ used in many experiments on anesthetized dogs to eliminate the effects of antidiuretic hormone on the kidney. It appears necessary in experiments in which an attempt is made to eliminate or to assess the effects of vasopressin upon a mechanism producing diuresis either to establish a maximum effective dose for the particular experimental cirmustances, or to examine the dose–response relationship between vasopressin and the diuresis in the particular experimental procedure.