Effects of different doses of acetylsalicylic acid on renal oxygen consumption.

The aim of the present study was to examine the acute effect of acetylsalicylic acid (ASA) on renal oxygen consumption (Qo2) and renal sodium excretion (UNaV) in anaesthetized dogs. With plasma salicylic acid (SA) concentrations ranging from 200-400 microgram/ml, Qo2 increased 36% (P less than 0.05) in spite of a 16% decrease in renal blood flow. At plasma SA concentrations of 80-200 microgram/ml Qo2 was significantly increased 45 min after the onset of ASA infusion. UNaV decreased from 97.7 to 21. 5 mumol/min (P less than 0.05). Glomerular filtration rate and absolute tubular reabsorption of sodium (RNa) was unchanged. The ratio RNa/Qo2 decreased from 31.0 to 21.3 (P less than 0.05). Renal lactate uptake increased. The results are most consistent with an uncoupling affect of ASA on oxidative phosphorylation in the kidney.