Comparative study of the effect of aflatoxin and some antitumour antibiotics on rat liver lysosomes in vivo and in vitro

Abstract

The effect of aflatoxin, one of the most potent hepatotropic carcinogens and antitumour antibiotics—mitomycin C and rubomycin C (identical daunomycin), on the activities of five rat liver lysosomal enzymes (acid deoxyribonuclease, arylsulphatases A and B, β-glucuronidase, β-glucosidase and β-galactosidase) has been investigated in vivo and in vitro. Large differences are found in the behaviour of lysosomal enzymes in response to the administration of aflatoxin and antibiotics. In the first hours after treatment with aflatoxin there is a marked activation of all the acid hydrolases. At the same time, the administration of mitomycin C and rubomycin C, cause a decrease in activity of most of the lysosomal enzymes. It is noted that only aflatoxin, both in vivo and in vitro, had a labilizing effect on lysosomal membranes, causing the release of the enzymes into the supernatant. The data are discussed in connection with the possible role of lysosomes in biochemical changes, accompanying carcinogenesis.