Effect of partial hepatic ischemia/reperfusion on choline acetyltransferase expression in hippocampal neuron in mice

Abstract

Objective To investigate the effects of partial hepatic ischemia/reperfusion (I/R) on choline acetyltransferase(ChAT) expression in hippocampal neuron in mice.Methods One hundred adult male mice,aged 2 months,weighing 20-25 g,were randomly divided into 5 groups (n =20 each): normal control group(group C),sham operation group(group S),groups I/R1,I/R2,I/R3.Partial hepatic ischemia was produced by clamping left hepatic artery and portal vein for 20,30,40 min respectively followed by reperfusion in groups I/R1,I/R2,I/R3.Passive avoidance task was performed with 10 mice in each group at 4-9 and 18-23 d after operation respectively.The animals were sacrificed and their brains were removed for determination of the expression of ChAT in CA3 of hippocampal neuron.Results Compared with group C,the latency was significantly shortened and number of errors increased in groups I/R1 and I/R2 at 4-7 d after operation and in group I/R3 at 4-9 d after operation,the expression of ChAT in hippocampal neuron down-regulated in groups I/R1,I/R2 and I/R3 at 9 d after operation( P ＜0.05 or 0.01).There was no significant difference in the latency and number of errors at 18-23 d after operation and the expression of ChAT in hippocampal neuron at 23 d after operation among groups C,I/R1,I/R2 and I/R3 ( P ＞ 0.05).Compared with group I/R1,the number of errors was significantly increased at 4 and 5 d after operation in group I/R2,the latency shortened at 4-6 d after operation and number of errors increased at 4-9 d after operation in group I/R3,and the expression of ChAT in hippocampal neuron down-regulated at 9 d after operation in groups I/R2 and I/R3 ( P ＜ 0.05 or 0.01 ).There was no significant difference in the latency and number of errors at 18-23 d after operation and the expresson of ChAT in hippocampal neuron at 23 d after operation among groups I/R1,I/R2 and I/R3 ( P ＞ 0.05).Conclusion Partial hepatic I/R can result in transient cognitive impairment in mice by down-regulating the expression of ChAT in hippocampal neuron. Key words: Liver; Reperfusion injury; Choline O-acetyltransferase; Hippocampus; Neurons