Localization of Tritiated Tetracycline in Mitochondria of Rat Liver Cells.

Abstract

Summary The localization of tetracycline labeled with tritium in the subcellular fractions of rat liver cells has been investigated. Ultracentrifugal analysis of cellular components revealed a significant and characteristic concentration of the drug in all fractions. Electrophoresis on paper and starch blocks of detergent-solubilized mitochondrial proteins revealed a distribution of the tetracycline, as determined by fluorescence and radioactivity, which coincided with the beta lipoprotein fraction of the mitochondrial lysate. Tetracycline in the presence of calcium ions is capable of precipitating the beta lipoprotein fraction of mitochondrial lysate as well as that of serum. The localization of TTC in fractions other than mitochondria is probably not related to complexing with lipoprotein.