The Effect of Galactosamine on the Activity of Lysosomal Peptidehydrolases of the Liver Depending on the Age of Rats[*]

Abstract

In order to elucidate the role of lysosomes during the development of hepatitis induced by D-galactosamine, the activities of cathepsin A, cathepsin D, and acid carboxypeptidase are measured in the liver after administration of a single dose of 375 mg D-galactosamine HCI per kg body weight This dose is able to induce hepatitis in young and adult, but not in newborn rats up to 4 weeks of age. Concommitantly, changes in lysosomal enzyme activities are not observed in the livers of newborn rats but in those of young and adult rats.

In order to correlate these observed alterations with the time after galactosamine administration, the lysosomal enzyme activities are measured at different times after injection of a single dose of D-galactosamine. The activities of lysosomal enzymes in the supernatant are elevated at 3 hours in the case of adult livers and at 6 hours in the case of young livers, indicating an early damage of the liver lysosomes after GaIN administration.

Key words

Galactosamine - Hepatitis - Lysosomal Enzymes - Age Dependency

1 Supplied by the Deutsche Forschungsgemeinschaft

1 Supplied by the Deutsche Forschungsgemeinschaft

2 The present paper contains results from the thesis of R.G.