Influence of variations in blood flow and of dinitrophenol on renal oxygen consumption

Abstract

Implications of the cell-separation theory relative to renal oxygen consumption were tested to determine a) if the tubular cells are able to extract oxygen more efficiently at reduced flows if additional oxygen is made available in physically dissolved form; b) if the renal parenchymal cells are able to extract oxygen more efficiently under the influence of an effective metabolic stimulant. It was found that, even when an additional quantity of at least 1 vol. % of oxygen was furnished to the kidney in physically dissolved form, the extraction of oxygen still remained constant over a wide range of renal blood flows. Since this was not attended by any alteration in the intrarenal hematocrit ratio, this finding was contrary to predictions based upon the cell-separation theory. Intravenous 2,4-dinitrophenol was found to increase the renal oxygen extraction very significantly, without altering the intrarenal hematocrit ratio. This implies that the capillary blood perfusing the renal tubules must not be virtually completely desaturated at normal or even moderately reduced flows, and is not consonant with the implications of the cell-separation theory.