Mechanism of shock induced Tumor necrosis factor and Prevention with Antibody

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Septic shock, include hypotension, fever, metabolic acidosis, continued to be high mortality rate despite the avalability of a wide variety or treatment. Tumor necrosis factor (TNF) has been implicated as a mediator of lethal endotxemia. The purpose of this study was to determine the efficasy of treatment of anti-TNF antibody in preventing the deterious effects of sepsis on a rabbits <Materials and Methods> (Antibody production.) Polyclonal anti-TNF was produced immunizing rabbits with human recombinant TNF (5X106u/ml, <20ng endotxin/mg TNF) (Neutralizing capacity of the antibody.) the neutralizing capacity of the antibody was determined by the TNF specific Enzyme-linked Immunosorbent Assay (ELISA) method. (Animal preparation) Japanese white rabbits, male, 3kg were utilized. Mean arterial pressure, blood gas, leukocyte counts, lysosomal enzyme and serum k was determined. (Experimental design) Sixteen rabbits were divided into two groups, anti-TNF sera treated group and control group. T … More NF rabbit sera or normal rabbit sera was infused, 30-45 min before injection of lipopolysaccharide (LPS). LPS 67mg/kg was infused intravenously. Physiological parameter was determined until 5 hr after the injection of LPS. Two ml of blood was obtained for assay of tumor necrosis factor at 30 min intervals. (TNF assay) TNF assay was quantified by measuring the cytotoxic effect of rabbit sera on L929 cells. <Result> In vitro neutralization of ant-TNF antibody activity. Dilution of 105 revealed the anti-TNF activity. In the control group, MAP fell 15-20% over 100-500min. In contrast MAP remained in the normal range in rabbits that were pretreated with anti-TNF antibody. Leucoeyte count was decreased in both group. beta-glucuronidase, and acid phosphatase was increased 2hr after LPS injection, but not so increased in ant-TNF antibody group. Blood gas analysis revealed more increase of serum K in control group than in anti-TNF group. Metabolic acidosis increased more in control group. Serum TNF activity level was increased 30 min after administration of LPS, peaked 60min, and returned to near baseline levels by 180 min. The mean TNF at 60 min increased significantly between in control group and in anti-TNF antibody group. Discussion and conclusion Pretreatment of anti-TNF antibody preveted a hypotension, metabolic acidosis, release of lysosomal enzyme. Protection of rabbit receiving anti-TNF antibody may be explained on the basis of improved peripheral perfusion in that systemic arterial pressure was elevated above that of the controls and cardiac output may have been supported. These studies provided support for the concept that TNF is an essential mediator of LPS induced inj ury and acts by initiating the primary changes that lead to the cascade of events culminating in lethal hypotensive shock. Less