Effect of cerebral ischemia-reperfusion injury on choline acetyltransferase activity related to study and memory in rat hippocampal tissue

Weijuan GAO; Jingfeng XUE

ABSTRACT

BACKGROUND:

The metabolism of acetylcholine in hippocampus reflects the function of cholinergic nervous system whose function is associated with learning and memory as well as intelligence.

OBJECTIVE:

To observe the changes of choline acetyltransferase activity in rat hippocampus after ischemia-reperfusion.

DESIGN:

Randomized controlled trial based on rats.

SETTING:

A Science and Research Department of Chengde Medical College.MATERIALSThe trial was conducted in the Central Laboratory of Chengde Medical College in 2002 and the subjects were 24 clean grade Wistar rats in equal number of the two sexes(weighting 260-280 g).

METHODS:

The 24 rats were randomly assigned into 3 groups ① Model groupIn this group the rats were made hyperlipemia and underwent bilateral carotid arteries blocking followed by reperfusion. ② Sham operation groupIn this group the rats were made hyperlipemia and underwent only exposure of bilateral carotid arteries without ischemia-reperfusion. ③ Normal control groupIn this group the rats received no intervention.The brains after the rats decapitated were harvested on the 1st 7th and 15th day respectively for colorimetric determination of the choline acetyltransferase activity in hippocampus.MAIN OUTCOME

MEASURES:

Determination of the choline acetyltransferase activity in the groups.

RESULTS:

None of the 24 rats was lost in the trial. ① The choline acetyltransferase activity in the model group on the 1st and 7th day was acetyltransferase activity in the model group on the 7th day was lower than that on the 1st and 7th day was lower than that in the normal controls[(0.037±0.006) μmol/g ·s, (0.017±0.006) μmol/g·s in model group vs (0.054±0.003) μ mol/g·s,(0.058±0.006) μmol/g·s in normal control group,P ＜ 0.01].② The choline acetyltransferase activity in the model group on the 7th day was lower than that on the 1st day. With repairing of ischemia-reperfusion injury,it recovered partially[(0.039±0.007) μnmol/g.s].③ Choline acetyltrans-ferase activity in sham operation group was not different from that in normal control(P ＞ 0.05).

CONCLUSION:

Simple exposure of carotid arteries does not change choline acetyltransferase activity.While ischemia-reperfusion can change the choline acetyltransferase activity and cause disorders of cholinergic nervous system function,which may be the reason for rat's intellectual disorders.