Effect of Endotoxin on Hemodynamics and Norepinephrine Metabolism in the Dog

Abstract

Summary

Intravenous administration of E. coli endotoxin to anesthetized dogs caused a precipitous fall in arterial blood pressure and renal artery flow within 3 min. With the fall in blood pressure, plasma ³H-norepinephrine fell to 63% of control levels. Five minutes after endotoxin administration, the ³H-norepinephrine level increased to 90% of the control value. Thirty minutes after endotoxin administration, blood pressure had risen to 75% of control levels and ³H-norepinephrine remained unchanged. ³H-Norepinephrine concentration in the atria, ventricle and kidneys remained unchanged, but the levels in the spleen and adrenals were significantly increased. In all cases ³H-normetanephrine levels increased suggestive of increased release and metabolism of catecholamines. It is suggested that endotoxin exerts certain changes in cellular permeability resulting in increased extraction of norepinephrine from the circulating blood.