[Proteolytic activity of lysosomes in various rat organs during total parenteral nutrition]. / Proteoliticheskaia aktivnost' lizosom v razlichnykh organakh krys v usloviiakh polnogo parenteral'nogo pitaniia.

Specific, total and nonsedimented activities of cathepsins A, B, C and D as well as of aryl sulfatases A and B, beta-galactosidase, beta-glucuronidase and N-acetyl-beta-D-glucosaminidase were studied in liver, kidney and spleen tissues of rats under conditions of artificial intragastric and parenteral nutrition. Activity of cathepsins A and D in liver tissue as well as total activity of all the lysosomal hydrolases studied in spleen was distinctly increased in parenteral nutrition. These data suggest elevation in the functional activity of lysosomal apparatus under conditions of parenteral nutrition.

[Lysosomal hydrolases of various rat organs in the process of cell nutrition]. / Lizosomal'nye gidrolazy razlichnykh organov krys v protsessakh kletochnogo pitaniia.

Activity of lysosomal proteinases cathepsins A, B, C, D, H and L was studied in liver, kidney, spleen, thymus, heart, skeletal muscle and brain tissues of rats, maintained on full value diet, on a diet free of proteins and on the diet enriched with methionine. Distinctly dissimilar reactions of thiol-dependent proteinases was detected in liver, heart tissues and skeletal muscles as compared with the reaction of cathepsins A and D; activity of cathepsins B, H and L was decreased 1.5-2-fold in the animal groups maintained on diets both free of proteins and enriched with methionine. The data obtained suggest that concentration of endogenous inhibitors of lysosomal thiol-dependent proteinases rather than content of SH-groups in tissues was responsible for alterations of their activity under conditions of protein starvation.