Relationship between iNOS expression and apoptosis in cerebral tissue, and the effect of Sini injection in endotoxin shock rats

ObjectiveTo investigate the dynamic changes and relationship of inducible nitric oxide synthase (iNOS) and apoptosis in endotoxin shock rats, as well as the effects of Sini injection.MethodsIn total, 102 Sprague-Dawley (SD) rats were randomly divided into a normal group (n=6, NG), sham operation group (n=24, OG), model group (n=24, MG), dexamethasone group (n=24, DG), and Sini group (n=24, SG). The endotoxin shock model was induced by an intravenous injection of lipopolysaccharide (LPS) (8 mg/kg). Rats in the OG, MG, DG, and SG groups were further divided into 4 groups: 1, 2, 3 and 6 h after shock groups (n=6 per group). iNOS expression was detected by immunohistochemistry. Terminal Deoxynucleotidyl Transferase Mediated Deoxyuridine Triphosphate-biotin Nick End Labeling (TUNEL) was employed to measure apoptosis.ResultsNo iNOS expression was found in the OG group. Compared with the OG group, iNOS expression in the MG group was markedly elevated, reached a peak at 1 h (P<0.01), decreased at 2 and 3 h, and rebounded at 6 h. Compared with the MG group, iNOS expression decreased significantly in both the DG (P<0.05) and SG (P<0.01) groups at 6 h. The number of apoptotic cells in the MG group was markedly increased than that in the NG and OG (P<0.01) groups, and reached a peak at 6 h. The number of apoptotic cells in the DG group at 1 and 2 h (P<0.01) and SG group at 2, 3 and 6 h (P<0.01) decreased when compared with the MG group.ConclusionSini injection can significantly inhibit NO generation, which decreases apoptosis and subsequently protects the brain from endotoxic shock.