Comparison Of The Effects Of Penehyclidine And Remote Ischemic Post-conditioning On Rat Liver After Lower-limb-ischaemia-reperfusion Injury

Objective To investigate and compare the effect of post-conditioning with penehyclidine and remote ischemic on liver peroxidation and inflammation in lower-limb-ischaemia-reperfusion rats.Methods One hundred and forty-four healthy male Wistar rats weighing 220-250g were randomly divided into four groups:control group (group C), lower-limb- ischemia-reperfusion group (LIR group), penehyclidine post-conditioning group (PHC group) and remote ischaemia post-conditioning group (RIPO group). Based on the duration of reperfusion, the rats in each group were randomly assigned to six sub-groups (n=6), no reperfusion (To), reperfusion for 1 (T1),3 (T2),6 (T3),12 (T4),24hours(T5). Lower-limb-ischaemia-reperfusion was performed by applying rubber bands at the bilateral trochanter major level for 3 hours, followed by reperfusion except in group C. After 2 hours and 57minutes of lower-limb ischaemia, penehyclidine was injected into the rats through the tail vein in PHC group, whereas the rats in IPO group were subjected to three episodes of 30-s ischemia at 30-s intervals. Liver function was evaluated by serum alanine transaminase (ALT), aspartate transaminase (AST) activities and hepatic pathology. Oxidative injury was assessed by malondialdehyde (MDA) content and superoxide dismutase (SOD) activity of the liver. Inflammatory level was reflected by myeloperoxidase (MPO) activity of the liver, tumour necrosis factor (TNF)-α, interleukin (IL)-10 levels in the serum and endotoxin concentration in the plasma.RESULTS Both the oxidative and inflammatory indices significantly increased after lower-limb-ischaemia-reperfusion. Furthermore, they were suppressed by either penehyclidine or remote ischaemic post-conditioning. Compared with group C, serum ALT and AST activities in group LIR were significantly higher from T1 to T5, serum ALT activity in group PHC was significantly higher from T2 to T5, serum ALT activity in group RIPO was significantly higher from T1 to T5, and serum AST activity in group PHC and group RIPO was significantly higher from T1 to T4 (P<0.05), in other three groups, MDA content in liver was significantly higher at T1 and T3 (P<0.05), SOD activity of liver in group LIR and RIPO was significantly lower from To to T5, while in group PHC it was significantly lower from T1 to T5 (P< 0.05), in other three groups, MPO activity in liver was significantly higher from T1 to T4 (P< 0.05), plasma endotoxin concentration and serum IL-10 assay was higher from To to T5 (P<0.05), serum TNF-a assay in group LIR was significantly higher at To and T1 (P<0.05), while in group PHC and group RIPO it was significantly higher at T1 (P<0.05); Compared with group LIR, serum ALT activity in group PHC was significantly lower from T1 to T3 while in group RIPO it was significantly lower at T3 (P<0.05),in group PHC and RIPO, AST activity was significantly lower from T1 to T4 and hepatic MDA content was significantly lower at T, and T3, and hepatic SOD activity was significantly higher from T1 to T5, and hepatic MPO activity was significantly lower from T1 to T3, and plasma endotoxin concentration was lower from T1 to T5, serum TNF-a assay was significantly lower at T1 (P<0.05), IL-10 assay in serum was significantly higher from T1 to T4 (P<0.05); Compared with group PHC, in group RIPO serum ALT, AST activities was significantly higher at T2 and SOD activity was lower at T1 and T2, plasma endotoxin concentration was higher at T1 and T3 to T5, serum TNF-a assay was significantly higher at T1, serum IL-10 assay was significantly lower from T2 to T4. The tissue sections obtained from group C and stained with H.E showed the following structure:the structure integrity of the hepatic lobule was intact; the hepatic cord was radially arranged; the liver cells were polygonal and the liver sinusoids were transparent. The hepatic cord in the LIR group at T2 and T3 was displaced or broken, and sinusoidal expansion and loose cytoplasm were detected, with the occasional appearance of ballooning and eosinophilic degeneration. The basic structure of hepatic lobules in group PHC and group RIPO was integrated at T2 and T3, no obvious degeneration was observed in liver cells, liver sinusoidal relatively neatly arranged.CONCLUSION LIR could induce distant hepatic damage of rats. Early lipid peroxidation, the accumulation of neutrophilic granulocyte and the release of inflammatory factors caused by lower limb ischemia reperfusion could be inhibited by either PHC or RIPO. Penehyclidine is superior to remote ischemic post-conditioning in protecting against hepatic injury induced by lower-limb-ischemia-reperfusion procedure in rats.