Evaluation of distal tubular function in aminoglycoside induced nephropathy

RESUMO

Acute metabolic acidosis potentiates the nephrotixicity of aminoglycosides by impairing the adequate excretion of ammonium and titratable acidity. The present study assesses distal tubular function after aminoglycoside administration in the rat. Two aminoglycosides, gentamicin and netilmicin were given to rats either in low doses equivalent to those used clinically (BG4 and BN5 groups) or in doses ten times higher (BG40 and BN50). The rats were subjected to acute metabolic alkalosis and the pCO2 of urine was continuously evaluated. the regression lines obtained by plotting the differences between urine and blood pCO2 as a function of urinary HCO3 in low dose models were simsilar to those obtained for the control group. However, the slopes obtained for BG40 and BN50 were significantly different from the control, suggesting an impairment of H+ secretion