Steady-state glucose oxidation by dog kidney in vivo: relation to Na+ reabsorption

Abstract

In eight experiments at normal or slightly elevated blood glucose concentration we quantified the steady-state renal glucose oxidation rate (see article) during control, at reduced Naomega absorptive rates (raised ureteral pressure), and during respiratory alkalosis. A tracer amount of either [1-14C]glucose or or [U-14C]D(omega)-glucose was infused at a constant rate into one renal artery. (see article) was calculated from the renal 14CO2 production rate (corrected for recirculation) and the specific activity of glucose in renal arterial blood. The control (see article) (n equals 8) equals 4.40 plus or minus 0.9 mumol/100 g-min (mean plus or minus SE). When net Naomega reabsorption was decreased by 45% (n equals 6), or when the pH of extracellular fluid was raised (n equals 2), no significant effect on (see article) (9.1 plus or minus 4.2 and 3.9 plus or minus 2.3 mumol/min-100 g, respectively) occurred. The mean glucose oxidation rate for all experiments was 5.65 plus or minus 1.73 mumol g-1-min-1 and required similar to 13% of the renal O2 utilization. Glucose oxidation provides energy either for basal renal work or for some portion of renal transport work not affected by increased ureteral pressure.