The Effects Of Cognitive Impairment In Hippocampus On Lipid Levels And Its Relations With The Expression Of HMG-CR In Liver

The relationship between cognitive function and hippocampus has been a research focus,but its impact on visceral activities is poorly knowned.Clinically,Alzheimer's patients are often associated with abnormal metabolism,there have been reports that up to 81%of sporadic Alzheimer's patients were with varying degrees of metabolism.Hydroxy-3-methylglutaryl coenzyme A reductase(3-hydroxy-3-methylglutaryl-Coenzyme A reductase,HMG-CR)is a key enzyme in lipid metabolism,this study investigated hippocampal cognitive impairment on plasma lipid levels and the relationship between the expression of hepatic HMG-CR to provide experimental basis for further study of lipid metabolism.To investigate the effects of cognitive impairment in hippocampus on lipid levels,a series of experiments were established.The A?1-42 was injected into the hippocampus of rats to build cognitive impairment model,automatic biochemical analyzer were used to detect lipid levels.The results showed that in the experimental group,the escape latency were(75.19±2.24)s,and the number of cross-platform were(1.68 ± 0.83)times,and the percentage of time in the platform quadrant were 17.33%±4.75%,Compared with the sham and control groups there were significant differences(P<0.05).In the experimental group,total triglyceride(TG)was(2.30±0.08)mmol/L;total cholesterol(TC)was(4.60±0.10)mmol/L and low-density lipoprotein(LDL)was(2.41 ±0.06)mmol/L,it was significantly higher than the sham group and the control group(P<0.05).To investigate whether lipid levels in rats are related to the apoptosis of hippocampal neuronal in rats or not,TUNEL method is used to test the apoptosis of hippocampal neuronal in rats.The results show that the index of the apoptosis of hippocampal neuronal of rats of the experimental group is 67.73 ± 4.38%,and indexes of false surgery group and control group are 19.88 ± 4.31%and 16.45 ± 5.50%respectively.Compared to the experimental group,there are significant differences(P<0.05).To investigate the expression of HMG-CR in liver of cognitive impairment in SD rats,a series of experiments were established,the expression of HMG-CRmRNA in liver was detected by RT-PCR,the expression of HMG-CR in liver was detected by Western Blot.The results showed that the expression of HMG-CRmRNA in liver of the experimental group was 0.49 ± 0.03,while significantly increased Comparing with the control group and the shamgroup(P<0.05).The expression of HMG-CR in liver of the experimental group was 0.50 ±0.02,while significantly increased Comparing with the control group and the sham group(P<0.05).In summary,A?1-42 were injected in the hippocampus of rats which can prepare hippocampal cognitive impairment model of rats successfully.Cognitive impairment in hippocampus can cause lipid levels elevating,which may be related to the increasing of the expression of HMG-CR in liver.