STUDYING OF TUMOR NECROSIS FACTOR and INTERLEUKIN RECEPTORS expression in hepatic TISSUE of ANIMALS PROTRACTEDLY RECEIVING NIMESULIDE

Aim. To study the immunohistochemical expression of TNFαR1 and IL-2Rα in hepatic tissue of animals (rats) with modeled NSAID-associated hepatitis. Materials and methods. The study of TNFαR1 and IL-2Rα in the hepatic tissue of experimental animals was carried out using antibodies TNFR1 (poly) 100 μl, bs-2941R, Rabbit Anti-TNF Receptor I Polyclonal Antibody (Bioss) and IL-2Rα (poly) 1 ml (М-19), sc-666 (Santa Cruz Biotechnology, INC), antibodies species-specific to rat tissue antigens. To reveal the antibodies, Uno Vue detection system, 100 tests, UMR 100PD, object-plates with polylysine coating Menzel were applied. The study was performed using the hepatic tissue of animal of experimental groups, who were administered nimesulide (Naiz®) during 21 days in the following doses: 0,5 mg/kg (therapeutic dose) ( n = 25); 2,5 mg/kg ( n = 20); 5 mg/kg ( n = 24). Intact animals ( n = 21) were used as the control. Antigen-positive cells were identified by the appearance of brown staining while examining preparations at light-optic level. The results of this reaction were assessed with semiquantitative method - in “crosses” (in connection with markers localization on the cellular membrane) and by the number of positively stained cells - in scores. Manifestation of markers expression was evaluated “in crosses” when successively examining the fields of vision under the microscope (from 10 to 20 in each histological section); according to the intensity of staining, the fields of vision were attributed to 4 groups: with negative reaction (-), weakly positive (+), positive (++) and distinctly positive (+++). The markers expression was assessed by a six-score system: 2 scores - up to 20% of stained cells; 4 scores - from 20 to 40 % of stained cells; 6 scores - more than 40 % of stained cells. Results. When studying immunohistochemical expression of TNFαR1in the hepatic tissue of rats with modeled NSAID-associated hepatitis, in all experimental groups there was observed immunopositiveness of the liver parenchyma and that of some cells of portal tract bile-ducts epithelium. Thus, when using nimesulide for a long time, the readiness of liver parenchyma epithelial cells to apoptosis, conditioned by the action of tumor necrosis factor, was stated. Conclusions. There was observed IL-2Rα expression in the liver parenchyma and in a part of bile-ducts of portal tracts among animals of all experimental groups that can be explained by the presence of autoimmune processes. Elevated TNFαR1 and IL-2Rα expression in the liver tissue was noted in animals of experimental group, who received a fivefold dose of nimesulide. Decreased expression of receptors in animals, who took a tenfold dose, can be associated with extensive necroses in the liver parenchyma.

Nonsteroid anti-inflammatory drugs, NSAID-hepatopathy, nimesulide, TNFαR1expression, IL-2Rα expression