[Can gentamicin nephrotoxicity in rats be modified by chronic administration of muzolimine?].

Some loop diuretics seem to increase gentamicin nephrotoxicity. We investigated this property for a new diuretic, muzolimine, in female Wistar rats. Each rat was given gentamicin intraperitoneally in a dosage that induces morphological and functional modifications in the kidneys (20 mg/kg/day for 7 days). Muzolimine was given in a daily dosage of 15 mg/kg starting 15 days before the first gentamicin injection and continuing throughout the seven-day gentamicin course. As compared to controls given gentamicin alone, modifications induced by the muzolimine-gentamicin combination showed no significant differences for the following criteria: renal accumulation of gentamicin, membrane lysosomal latency, renal oxidative mitochondrial metabolism and cortical activity of renal cathepsin B, N-acetyl-beta-D-glucosaminidase (NAG) and alanine aminopeptidase. However, slightly lower sphingomyelinase activities (p less than 0.05) were found for muzolimine + gentamicin as compared to gentamicin alone. Urinary NAG excretion increase more with muzolimine + gentamicin than with gentamicin alone, perhaps as a result of the very significant increase in urinary output observed with the diuretic. Our results show that, in contrast to findings with another loop diuretic, furosemide, the renal toxicity of gentamicin is not noticeably modified by concomitant administration of muzolimine.