Effect on vitamin A on the development of galactosamine-induced hepatitis in rats.
In order to elucidate the role of lysosomes in experimental hepatitis caused by D-galactosamine in rats the activities of cathepsin A and D and acid carboxypeptidase were measured. Enzyme activities were assayed in liver homogenate, lysosomal supernatant fraction and lysosomal sediment fraction. Lysosomal enriched fractions were prepared according to De Duve. Vitamin A in high doses aggravates the morphological alterations observed in galactosamine treated rats. At the same time the labilization of lysosomes increases substantially. This effect was induced by doses of retinyl-palmitate that normally caused only an activation of Kupffer cells and no significant liberation of lysosomal peptidehydrolases. The activities of cathepsin A and D increased 2-fold in liver homogenate after combined treatment with galactosamine and vitamin A, whereas the activity of acid carboxypeptidase decreased markedly.
D000818:Animals; D002268:Carboxypeptidases / Q000032:analysis; D002403:Cathepsins / Q000032:analysis; D002474:Cell-Free System; D056486:Chemical and Drug Induced Liver Injury / Q000473:pathology*; D005260:Female; D005688:Galactosamine; D007728:Kupffer Cells / Q000187:drug effects; D008099:Liver / Q000201:enzymology; D008247:Lysosomes / Q000201:enzymology; D051381:Rats; D014801:Vitamin A / Q000494:pharmacology*
D014801:Vitamin A; D005688:Galactosamine; D002268:Carboxypeptidases; D002403:Cathepsins