[The influence of adhesion molecules expression to neutrophil aggregation in liver after severe burns].

Objective: To elucidate the mechanism of neutrophil aggregation in the liver and the influence of the expression of adhesion molecules after severe burns during early postburn phase, and to explore simultaneously the mechanism of liver damage after severe burns.

Methods: 1. The morphology of the liver and the activation of MPO were observed. 2. The human hepatocytes and hepatic sinusoidal endothelial cells (HSECs) were isolated and cultured, the flow cytometry and micropipette aspiration system were used to observe dynamically the change in intercellular adhesive force between neutrophils and hepatocytes under the influence of burn patient sera. Also the changes in the expression of P-selectin and ICAM-1 on the hepatocytes and HSECs under the influence of burn patient sera were studied.

Results: 1. MPO activation was significantly higher than that in the control group, and reached its peak at 6 hours. Three pieces of liver tissue at 6, 12, 24 hours were examined, and it was found that the Disse's spaces were wide and filled with a great number of PMNs. 2. A constitutive expression of P-selectin and ICAM-1 was found in normal hepatic sinusoidal endothelial cells but not in normal hepatocytes. Under the influence of burn patient sera, the expression of P-selectin increased significantly at 1 hour (P < 0.01) in hepatic sinusoidal endothelial cells but not in hepatocytes, and the expression of ICAM-1 increased significantly at 1 and 2 hour (P < 0.01) in hepatocytes and hepatic sinusoidal endothelial cells. 3. In the presence of burn patient sera, the intercellular adhesive force between neutrophils and hepatocytes reached its peak level at 2 hour after co- cultivation and declined thereafter due to the aggravation of hepatocytic injury. After using ICAM-1 Mab in cultured hepatocytes, the adhesive force reduced significantly.

Conclusion: Neutrophil aggregation in the liver was confirmed after severe burns during early postburn phase. The expression of P-selectin and ICAM-1 on the hepatocytes and HSECs played key roles to neutrophil aggregation in liver after severe burns during early postburn phase, inducing the participation of neutrophils in hepatocyte injury.