Objective: To investigate the effect of nitric oxide (NO) on Toll-like receptors 2 and 4 (TLR 2/4) gene expression in the liver in acute hemorrhagic necrotizing pancreatitis (AHNP) in rats.
Methods: Seventy SD male rats were randomly divided into sham-operated group (n=10), AHNP group (n=30) and L-arginine (L-Arg) treatment group (n=30). Blood samples and liver tissues were obtained at 6 hours in sham-operated group, and 3, 6, 12 hours respectively in AHNP group and L-Arg-treated group. Alanine aminotransferase (ALT), aspartate aminotransferase (AST), amylase in serum, NO, tumor necrosis factor-alpha (TNF-alpha) in liver tissue were determined. TLR2/4 mRNA expressions in the liver tissue were measured by reverse transcription polymerase chain reaction (RT-PCR).
Results: TLR2/4 mRNA could be detected in the liver with low values in sham-operated group [(1.150+/-0.725)x10(-6), (11.450+/-1.724)x10(-4)], but they were markedly upregulated at 3 hours in AHNP group [(1.970+/-0.362)x10(-3), (175.000+/-0.111)x10(-3)], and peaked at 12 hours [(29.400+/-3.155)x10(-4), (267.300+/-8838)x10(-2), P<0.01). At the same time serum levels of amylase, ALT and AST increased, hepatic injuries were aggravated, the levels of TNF-alpha in the liver were increased and levels of NO in the liver were lowered (P<0.05 or P<0.01). Treatment with L-rg could effectively inhibit TLR2/4 mRNA expression [3 h: (3.510+/-1.528)x10(-4), (13.500+/-2.231)x10(-2); 6 h: (21.000+/-5.346)x10(-4), (18.700+/-2.685)x10(-2); 12 h: (26.200+/-2.076)x10(-4), 1.959+/-0.270, P<0.05 or P<0.01] and alleviate hepatic injuries. The levels of serum amylase, ALT and AST lowered, and the levels of TNF-alpha in the liver were lowered and the levels of NO were markedly increased (P<0.05 or P<0.01).
Conclusion: These findings suggest that the expression of TLR2/4 mRNA is increased in the liver in AHNP, and the hepatic injuries are aggravated. NO could markedly inhibit TLR 2/4 mRNA gene expression in the liver in AHNP.