Reparative and Antioxidant Effects of New Analogues of Immunomodulator Thymogen in Experimental Model of Liver Damage

We studied the reparative and antioxidant effects of Thymogen and its new structural analogues obtained by binding amino acid D-Ala to the N- or C-end of the peptide molecule in acute toxic hepatopathy. Intragastric administration of carbon tetrachloride for 5 days caused the development of fat degeneration of hepatocytes, a decrease in catalase activity, and an increase in malondialdehyde concentration. Administration of peptides suppressed oxidative peroxidation and stimulated reparative regeneration of hepatocytes; Thymogen analogues produced more pronounced hepatotropic and antioxidant effects than Thymogen. Inclusion of D-Ala enhanced the effect of Thymogen on the processes of regeneration in hepatocytes and the antioxidant effect under conditions of acute carbon tetrachloride hepatopathy. The highest efficiency was achieved when the amino acid was added to the C-end of the molecule.

DSLET and ACTH(4-10) increase mitotic activity of hepatocytes and suppress antibody production

The mitotic index of hepatocytes remained unchanged after 10 intraperitoneal injections of DSLET and ACTH(4-10) in doses of 0.5, 1.5, and 5 microg/kg, but increased after injection of these substances in doses of 50 and 150 microg/kg. DSLET in doses of 5, 50, and 150 microg/kg decreased the number of antibody-producing cells in the spleen. ACTH(4-10) possessed immunosuppressive activity not only in these doses, but also in a dose of 1.5 microg/kg. As differentiated from mitotic activity of hepatocytes, the degree of immunosuppression increased with increasing the dose of test peptides.

Tripeptide Gly-His-Lys is a hepatotropic immunosuppressor

Ten intraperitoneal injections of tripeptide Gly-His-Lys in doses of 1.5, 5, 50, 150, and 450 mg/kg stimulated mitotic activity of hepatocytes and dose-dependently suppressed immune reactivity (number of antibody-producing cells and delayed-type hypersensitivity reaction).