Effect of vasoactive intestinal peptide (VIP) on cytokine levels and haemostatic and biochemical parameters in a rat endotoxaemic model

The presented study was planned to determine whether vasoactive intestinal peptide (VIP) could prevent cytokine haemostatic, haematological, and biochemical disturbances in LPS-treated rats. Adult male Wistar rats (weight range: 200-250 g) were used. The study included four groups: group 1 served as a control group (C); animals in group 2 were given intravenously 1.6 mg/100 g of LPS (E. coli, serotype 0.111:B4); in group 3, rats were injected intraperitoneally with 25 ng/kg of VIP; in group 4, the same doses of VIP and LPS were injected simultaneously. Blood samples were collected 6 h after treatments. In endotoxaemic rats, platelet count, fibrinogen, and antithrombin levels were decreased, the activated partial thromboplastin time and prothrombin time were prolonged, and leucopoenia, as well as significant changes in differential leukocyte percentage were demonstrated. In addition, LPS caused statistically significant increases in plasma TNF-a, IL-6, and IL-10 levels, and AST, ALT, creatinine, cholesterol, triglyceride concentrations. However, it caused a statistically significant decrease in total protein and albumin levels when compared to control group. The results showed that during endotoxaemia, VIP had moderately therapeutic effect as an antiinflammatory agent, suppressing TNF-α and IL-6, and stimulating IL-10; however, it was not effective against the adverse effect of LPS on investigated haematological and biochemical parameters.