Correlation of plasma catecholamine levels with hemodynamic changes in canine endotoxin shock.

Abstract

Plasma catecholamine levels during canine endotoxin shock were measured by a discriminating trihydroxyindole assay method. A typical pattern of hemodynamic changes occurred with doses of endotoxin ranging from 0.05 to 2.0 mg per kg. Plasma epinephrine rose at the onset of hypotension and then returned to normal within 4 hours. No consistent elevation of norepinephrine was observed. A slow infusion of endotoxin produced a gradual decline in blood pressure with a close correlation between the degree of hypotension and the level of epinephrine. Resistance to endotoxin was unrelated to either the severity of the early hemodynamic response or the level of plasma epinephrine. In dogs with cervical cord section or adrenalectomy circulating catecholamines did not appear to be necessary for the initiation of endotoxin shock and was accelerated in the absence of these amines.