Effects of KW-1062, a new aminoglycoside antibiotic, and gentamicin on the kidney were compared. KW-1062 (5, 10, 20, 40 and 80mg/kg) and gentamicin (5, 10, 20 and 40mg/kg) were intramuscularly administered to male Wistar strain rats for 30 days. On the 5th, 15th and 30th day, renal disturbances were examined by light microscopy. On the 30th day, electron microscopy was also carried out.
Light microscopic examination revealed that degeneration of the renal tubular epithelium and the round cell infiltration were seen on the 5th day in the group received gentamicin 5mg/kg. On the 15th and 30th day, these changes were dose-dependent.
In the group given KW-1062 40mg/kg, degeneration of the renal tubular epithelium and the round cell infiltration were recognized on the 15th day. Electron microscopic examination revealed dense body containing myelin-like structures in the epithelial cell of the portio principal in proportion to dose in the group received gentamicin 5mg/kg. At gentamicin 40 mg/kg, myelin-like structures were collected in the renal tubular cavity and obstructed it.
With KW-1062 20mg/kg or more, similar findings to those of gentamicin 5mg/kg were obtained, however, severe disturbance such as the obstruction of the renal tubular cavity was not recognized.
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