The Effect of TLR4 Blockade on Some Indicators of Systemic Inflammatory Response to Proteus mirabilis LPS in Rats

The effects of TLR4 blocker on blood cell morphology, concentrations proinflammatory cytokines, and functional state of the liver and kidneys were studied in outbred male rats (n=60) after intravenous injection of 20 mg/kg LPS isolated from opportunistic Proteus mirabilis strain ATCC 51393. TLR4 blocker TLR4-IN-C34 was injected intravenously in a dose of 1 mg/kg/day over 3 days. Systemic inflammatory reaction induced by LPS was characterized by elevation of serum TNFα, IL-1β, IL-6, erythrocyte sedimentation rate, leukocytosis, and thrombocytosis. Increased activity of hepatocyte enzymes (ALT, alkaline phosphatase, and lactate dehydrogenase), retention of nitrogen metabolites (urea and creatinine), elevated content of protein oxidation products, and enhanced protein catabolism were also observed. Administration of TLR4 blocker reduced parameters of inflammatory reaction and prevented the development of hypercatabolic syndrome; endotoxicosis and kidney function indicators approached the normal levels.