Studies on gentamicin-induced labilization of rat kidney lysosomes in vitro. Possible protection by selenium

The labilizing effect of gentamicin, an aminoglycoside antibiotic, on isolated rat kidney lysosomes was investigated. The light-scattering behavior of lysosomal suspensions and the release of lysosomal acid hydrolase enzymes (acid phosphatase, beta-glucuronidase and muramidase) from incubated lysosomal suspensions, in the presence of gentamicin, were used as indices of lysosomal membrane labilization. Gentamicin was found to cause a decrease in light absorbance and a release of lysosomal acid hydrolases, which indicate lysosomal membrane swelling. In the presence of selenium, in the form of potassium selenate, the decrease in light absorbance of lysosomal suspensions and the release of lysosomal acid hydrolases from isolated lysosome particles were reduced markedly. This suggests that selenium protects against gentamicin-induced lysosomal membrane labilization. The possible mechanisms of protection by selenium are discussed.