Renal clearances at rest and during physical exercise after injection of bacterial pyrogen

Abstract

Clearance of inulin (CIn)and para-aminohippuric acid (CPAH). cardiac output, oxygen uptake, and arterial blood pressure were measured in 5 healthy subjects at rest and during supine exercise on a bicycle ergometer before and after infection of a bacterial pyrogen (purified lipopolysaccharide, Pyrexal). CPAH was 45-145% higher at rest during the flush phase than in the normal condition. The increase in CIn was less. Cardiac output increased also. The renal fraction of the cardiac output was larger than in the normal condition. During moderate exercise in the flush phase, CPAH decreased from the values before work. This decrease was usually larger than in the normal condition. The pyrogen-induced increase in cardiac output was less during exercise than at rest. A pronounced renal vasoconstriction during exercise is demonstrated even after the injection of bacterial pyrogen.