The effect of bacterial pyrogen on the distribution of intrarenal blood flow

Abstract

Hemodynamic and biochemical measurements were made before and 90 min after 50 [mu]g of Pseudomonas-derived pyrogen was infused into nine awake dogs. Six control dogs received no pyrogen. Total renal blood flow (RBF) and intrarenal distribution of blood flow to four equal cortical zones (outer to juxtamedullary) were determined by the radioactive microsphere method. Pyrogen administration produced tachycardia, pyrexia, polyuria, natriuresis, and increased RBF. Cardiac output, arterial pressure, hematocrit, creatinine clearance, and white blood cell count did not change significantly. Despite increased total RBF, distribution of blood flow within the renal cortex did not change significantly after pyrogen administration. When compared with the effect of live bacteria, these studies suggest that polyuria and natriuresis result from any increased juxtamedullary blood flow without being dependent on redistribution, per se. Furthermore, the detrimental renal effect of bacterial sepsis may be related to the relative outer cortical hypoperfusion in contrast to the benign renal effect of pyrogen where no redistribution of blood flow occurs.