Gentamicin-induced nephrotoxicity in mice: protection by loop diuretics.

Gentamicin, at doses of 50 or 100 mg/kg body wt administered daily to healthy male MF1 mice by i.p. injection for either 7 or 10 days caused proximal tubular cell damage shown both by the urinary excretion of N-acetyl-beta-D-glucosaminidase (NAG) and by electron microscopy. The tubular damage was maximal at 7 days. Concomitant administration of any of 3 diuretics-frusemide, bumetanide or piretanide at 5,0.5 and 1 mg/kg body wt/day respectively-resulted in less tubular damage than that caused by gentamicin alone. This finding of protection by diuretics contrasts with those of previous studies of combination gentamicin-diuretic therapy.