Hormonal and Hemodynamic Responses to 15 ml/kg Hemorrhage in Conscious Dogs: Responses Correlate to Body Temperature

Abstract

Abstract

Hemorrhage stimulates the secretion of ACTH, corticosteroids, vasopressin, and renin. Elevated levels of these hormones may be required for the restoration of normal blood volume and pressure. These experiments were designed to quantitate the simultaneous responses of these hormones after 15 ml/kg hemorrhage in conscious dogs. Nine conscious dogs were bled 15 ml/kg from chronically maintained femoral arterial catheters. In 20 experiments, the hormonal and hemodynamic responses to the hemorrhage were not reproducible from dog to dog or from experiment to experiment in dogs studied more than once. The dogs'rectal temperatures ranged from 38.2 to 41°, although nearly all appeared normal and healthy at the time of study. Most of the variability in the data could be explained on the basis of these differences in rectal temperatures. The dogs with elevated rectal temperatures (39-41°) had higher resting heart rates, ACTH, corticosteroids, vasopressin, and plasma renin activity, and greater blood pressure, ACTH, corticosteroid, and vasopressin responses than normothermic dogs (rectal temperatures 38-39°). We conclude that (i) not all dogs that appear to be healthy respond to hemorrhage equally; (ii) the variability of hormonal and hemodynamic responses to hemorrhage in a random sample of conscious dogs can be reduced by preselection of animals on the basis of rectal temperature.