[Protective effect of polyenylphosphatidyl choline on liver in rat with sepsis]

To investigate the protective effect of polyenylphosphatidyl choline (PPC) on liver in rat with sepsis.

A total of 50 healthy male SD rats were randomly divided into four groups according to random number table: normal control group (NS group, n=10), sepsis model group (LPS group, n=15), PPC control group (PPC group, n=10) and PPC protection group (P+L group, n=15). A single dose of lipopolysaccharide (LPS) 6 mg/kg was injected to the peritoneal cavity to reproduce the sepsis model, while in NS group and PPC group, same volume of normal saline was used. PPC 10 ml/kg (232.5 mg/kg) was injected 24 hours and 6 hours before LPS via the tail vein in PPC group and P+L group, while in NS group and LPS group 5% glucose solution in the same volume was given. Behavioral changes and mortality rate of rats were recorded, and all survived rats were sacrificed 24 hours after LPS injection. Venous blood was taken for alanine aminotransferase (ALT) and aspartate aminotransferase (AST) determination. Ratios of liver weight/body weight (L/Wb) and wet weight/dry weight of liver (W/D) were calculated. Histopathology changes in liver tissue were observed with hematoxylin eosin (HE) stain, and intercellular adhesion molecule-1 (ICAM-1) expression with instant two-step immunohistochemistry.

Twenty-four hours after LPS injection (LPS group), the rats became lethargic, with less activity and drinking, while rats in P+L group, showed much better mental status, water intake and activity than LPS group. The mortality rate of P+L group was significantly lower than that of LPS group [6.7% (1/15) vs. 46.7% (7/15),P<0.05]. Compared with LPS group, rats in P+L group had lower levels of plasma ALT and AST, L/Wb, W/D , and liver ICAM-1 positive expression ratio [ALT (U/L): 157.71 ± 32.63 vs. 225.63 ± 43.47; AST (U/L): 53.21 ± 13.85 vs. 85.25 ± 18.91; L/Wb: (4.09 ± 0.28)% vs. (4.50 ± 0.25)%; W/D : 3.52 ± 0.27 vs. 3.84 ± 0.18; ICAM-1 positive expression ratio: 35.7% (5/14) vs. 87.5 (7/8),P<0.05 or P <0.01]. All parameters were normal in NS group and PPC group, and no statistical significance was observed between them (all P >0.05). LPS-injection led to severe inflammatory reaction in hepatic tissue , including obvious edema of hepatic parenchymal cells, exudation and aggregation of inflammatory cells, while in P+L group, these morphological changes were milder than that in LPS group but more obvious than that of NS group.

Pre-treatment of rats with PPC alleviates progressive inflammatory disturbances of hepatic tissue caused by endotoxin injection, and it attenuates liver edema and ICAM-1 expression, protects liver function and decreases mortality rate in rats with sepsis.