Toxicological Approaches to Streptothricin Antibiotics. I. Implications of Delayed Toxicity in Mice

Abstract

In order to investigate the mode of the delayed toxicity of streptothricin antibiotics, racemomycin-A and -D were administered intravenously to mice in a surviving dose. Antimicrobial activity levels in serum declined very rapidly. Localized distribution of antibiotics was conspicuous in the kidneys, and binding rate of the antibiotics with serum proteins in vitro was related to β-lysine units in the molecule. Mice administered with antibiotics showed gradual decrease in their body weight, and they further suffered prominent damages in their liver, spleen, and kidneys. These lesions seemed to kill the mice by the delayed toxicity. The mice that died by the lethal doses of the antibiotics were considered to be due to the respiratory paralysis.