Immunity mechanism of ischemia postconditioning in preventing from hepatic ischemia-reperfusion injury in liver cirrhotic rats

Abstract

Objective To investigate the protective effects and its mechanism of ischemia postconditioning (IPO) in hepatic ischemia-reperfusion injury (IRI) in liver cirrhotic rats. Methods Thirty liver cirrhotic Sprague-Dawley (SD) rats were randomly divided into three groups according to the random table methods: ischemia postconditioning (IPO) group, IRI group, and pure hepatectomy (PH) group with 10 rats in each group. Rats in IPO group underwent partial hepatectomy (40%), and the first portal was occluded for 20 min, then 3 times of ischemia-reperfusion were performed, and finally continuous reperfusion. Rats in IRI group underwent partial hepatectomy (40%), and the first portal was occluded for 20 min, then continuous reperfusion was performed. Rats in PH group underwent partial hepatectomy (40%) only. Inferior vena cava blood was collected at 6, 24 h after operation. Levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), proportion of cluster of differentiation (CD) 4+, CD8+, regulatory T cells (Treg) and levels of interleukin (IL)-4, IL-10 were tested. Comparison of three groups was conducted by one way analysis of variance and pairwise comparison by LSD-t test. Results After 6 h reperfusion, levels of ALT and AST in IPO group [(1 623±378) , (1 993±469) U/L] were significantly lower than those in IRI group [(2 690±549) , (3 020±577) U/L] (LSD-t=-4.21, -3.72; P<0.05). After 24 h reperfusion, levels of ALT and AST in IPO group [(307±76) , (555±137) U/L] were still significantly lower than those in IRI group [(518±105) , (1 050±355) U/L] (LSD-t=-4.06, -3.37; P<0.05). After 6 h reperfusion, proportion of CD4+, CD8+, CD4+/CD8+ ratio, Treg, and levels of IL-4, IL-10 in IPO group were (57±5) %, (25±3) %, 2.3±0.5, (8.9±0.4) %, (1.27±0.25) mg/L, (0.61±0.03) mg/L, respectively. While in IRI group, they were (52±6)%, (12±3) %, 4.5±0.8, (7.3±0.3) %, (0.66±0.11) mg/L, (0.34±0.06) mg/L, respectively. In IPO group, CD8+, Treg, IL-4 and IL-10 increased significantly, while CD4+/CD8+ ratio decreased significantly, compared with those in IRI group (LSD-t= 7.74, 6.67, 5.52, 9.31, -6.69; P<0.05). Conclusion IPO can prevent from hepatic IRI injury in liver cirrhotic rats through decreasing the immune injury. Key words: Reperfusion injury; Rats; Liver cirrhosis, experimental; Ischemic postconditioning; T-lymphocyte subsets; Interleukin-4; Interleukin-10