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.MATERIALS:The 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 group:In this group the rats were made hyperlipemia and underwent bilateral carotid arteries blocking followed by reperfusion. ② Sham operation group:In this group the rats were made hyperlipemia and underwent only exposure of bilateral carotid arteries without ischemia-reperfusion. ③ Normal control group:In 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.

Objective To investigate the damage of hippocampal neurons induced by chronic cerebral ischemia in the rats,and to clarify its mechanism.Methods 90 healthy adult male SD rats were randomly divided into sham operation group (n=30 ) and experimental group (n=60 ). The chronic cerebral ischemia rat models were established by permanently ligating the common carotid arteries on both sides of the rats in experimental group.The rats in sham operation group were established by incising the cervical median,only the common carotid arteries on both sides were separated without ligating. The rats in sham operation group and experimental group were respectively sacrificed at the 7th,14th and 21st day after operation.At each time point 10 rats in sham operation group and 20 rats in experimental group were selected and sacrificed.Immunohistochemistry staining was used to observe the dynamic changes of the expression levels of choline acetyltransferase(ChAT)in hippocampus neurons, and TA-FE method was used to observe the dynamic changes of hippocampal microvascualr architecture. MiVnt image analytical system was used to quantitatively analyze the immunohistochemistry result,the microvessel density (MVD)and micorvessel area density (MVA)of horizontal part of hippocampus in the rats. Results Compared with sham operation group,the ChAT expression levels in hippocampus neurons of the rats in experimental group at different time points were significantly decreased(P<0.05);and with the prolongation of time,the ChAT expression levels were gradually decreased;the ChAT expression level in 14-day experimental group was significantly lower than that in 7-day experimental group (P<0.05 );the ChAT expression level in 21-day experimental group was significantly lower than those in 7-day and 14-day experimental groups(P<0.05).The MVD and MVA of hippocampus of the rats in experimental group at different time points were obviously decreased compared with sham operation group(P<0.05);the MVA was gradually decreased with the prolongation of time, and the MVA of hippocampus of the rats in 21-day and 14-day experimental groups were obviously decreased compared with 7-day experimental group(P<0.05);the MVD was gradually decreased with the prolongation of time,the MVD of hippocampus of the rats in 21-day and 14-day experimental groups was obviously decreased compared with 7-day experimental group(P<0.05);the MVD of hippocampus of the rats in 21-day experimental group was obviously decreased compared with 14-day experimental group(P<0.05).Conclusion Chronic cerebral ischemia can lead to the progressive decrease of the ChAT expression level,MVD and MVA of hippocampus of the rats to aggravate gradually the learning and memory dysfunction, which may be one of the reasons of vascular dementia.

Objective:To investigate the effect of dietary cholesterol on hepatic TG accumulation in rats. Method:Fourteen male Wistar rats were randomly divided into 2 groups and fed 1% cholesterol or cholesterol free AIN76 diets. After 4 w,serum triglyceride(TG) ,total cholesterol(TC) ,high density lipoprotein cholesterol(HDL-C) ,phospholipids(PL) ,glucose and free fatty acid(NEFA) levels were determined. Hepatic lipid concentrations(TG,TC,PL) and the activities and/or mRNA expression of malic enzyme(ME) ,glucose-6-phosphate dehydrogenase(G6PDH) ,fatty acid synthase(FAS) ,phosphatidate phophatase(PAP) ,carnitine palmitoyl transferase(CPT1,2) ,HMG-CoA reductase,acylCoA-cholesterol acyltransferase(ACAT) ,cholesterol 7?-hydroxylase(CYP7A) were also determined. Results:The serum TC and non-HDL-C levels were significantly increased but TG and HDL-C levels were significantly decreased by cholesterol feeding. The concentrations of hepatic TC and TG were 4-20 folds higher in cholesterol group than those in cholesterol free group. The activities of hepatic ME,G6PDH,FAS,PAP and CPT were depressed by cholesterol(40%,70%,50%,15% and 25% respectively) . The mRNA expression of FAS,CPT1,CPT2,and HMG-CoA reductase were down-regulated(35%,30%,50% and 25% respectively) and CYP7? and ACAT were up regulated(6.5 and 1.6 fold) by cholesterol in liver. Conclusion:The dietary cholesterol increases TG accumulation in liver,but dose not stimulates the activity and the gene expressionof hepatic TG synthesis related enzymes.

Objective: To study the antioxidative and hepatoprotective activities of low molecular fucoidan oligosaccharides(LMFO) from Laminaria japonica in mice.Methods: Mice were pretreated with LMFO(50?100?150 mg/kg ig respectively, 10 days),and then 0.2 % CCl 4 10 ml/kg ig and D-GalN(600 mg/kg)+LPS(lipopolysaccharide,1 ?g/kg) ig respectively in two model groups to induce liver injury. Liver injury was assessed by quantifying activities of plasma GPT, SOD, GSH-Px and MDA content.Results: The increase of plasma GPT activity was significantly inhibited by LMFO in two liver injury models, suggesting that LMFO had good protective effect on the hepatocytes. LMFO had good antioxidative effect in mice with liver injury induced by CCl 4 and D-GalN+LPS as indicated by decreased MDA content and increased activities of plasma SOD and GSH-Px. Conclusion: LMFO is protective against CCl 4-induced and D-GalN+ LPS induced liver injury in mice and its effect may be due to its antioxidative activities in vivo.

Objective To investigate the effects of sericin pretreatment on the expression of extracellular matrix(ECM) associated protein in diabetic nephropathy(DN) rats' kidney.Methods Sixty six male SD rats were randomly divided into 3 groups(n=12):normal control group,DN model group and sericine pretreatment group.DN rats model in model group and sericine pretreatment group were established by intraperitoneally injection of streptozotocin(STZ).Blood glucose≥16.7 mmol/L was taken as the standard of successful modelization.The rats in sericine pretreatment group were lavaged with sericine(2.4 g·kg~(-1)·d~(-1)) for 35 days before injecting STZ.The enzymic method was used to measure the blood glucose.Type Ⅳ collagen(cⅣ)and laminin(LN)content in the serum were detected by ELBA.The expression of transforming growth factor-β_1,(TGF-β_1)and tissue inhibitors of maprix metalloproteinase-1(TMP-1) protein in the kidney was observed by immunohistochemical staining.The expression of Smad 3 protein in the kidney was detected by Western blot.Results Compared with normal control rats,the blood glucose,cⅣ and LN content in the serum,TGF-β_1,TIMP-1 and Smad 3 expression in the kidney of the model group rats increased obviously(P<0.01).The blood glucose,cⅣ and LN content in the serum,TGF-β_1,TMP-1 and Smad3 expression in the kidney of rats in sericine pretreatment group were significantly lower than those of the rats in model group(P<0.01).Conclusion Sericin pretreatment can inhibit the activation of TGF-β/Smad 3 signal pathway in the kidney of DN rats,and prevent the decrease of MMPs activity induced by up-regulation of TIMP-1.So sericin can prevent accumulation of ECM and glomerulosclerosis during DN,and has satisfactory apotropaic effects on the development of DN.

Objective:To study the effects of different molecular weight of collagen polypeptides from Apostichopus japonicus (A1:6 000U

10000 u,SP2:6 000 u0.05),the melanogenesis and tyrosinase activity were inhibited remarkably(P

Objective To investigate the mechanism of orotic acid-induced fatty liver in rats. Method Rats were randomly divided into 2 groups,and fed AIN93 diet with or without 1% orotic acid (OA) for 10d. Serum total cholesterol (TC),triglyceride (TG),high density lipoprotein-cholesterol (HDL-C),hepatic lipids concentrations (TG,TC and phospholipids),hepatic enzymes activities and mRNA levels of key enzymes related to lipids metabolism,as well as hepatic genes expression of transcription factors were determined. Results OA administration significantly increased serum and hepatic TG concentration. The activity and mRNA level of fatty acid synthase (FAS) were obviously up-regulated by OA treatment,whereas the activities and mRNA concentrations of carnitin palmitoyl transferase (CPT) and microsomal triglyceride transfer protein (MTP) were depressed significantly. Furthermore,OA also stimulated the mRNA expression of sterol regulatory element binding protein-1c (SREBP-1c),but did not alter the mRNA concentrations of peroxisome proliferator-activated receptor alpha (PPAR?) in liver. Conclusion:The stimulation of TG synthesis caused by enhancement of SREBP-1c and its target genes-FAS,which could be responsible for development of fatty liver. On the other hand,the inhibition of fatty acid beta-oxidation and VLDL secretion were related to the observed lipids accumulation.

AIM: To investigate the influence of Sini decoction (SND) on the proliferation and apoptosis of rabbit abdominal aorta smooth muscle cells after ballon injury and discuss the effect of vascular smooth muscle cell's (VSMCs) proliferation and apoptosis in post-percutaneous coronary intervention (PCI) restenosis (RS) and the feasibility of SND preventing post-PCI RS. METHODS: The animal model of rabbit abdominal aorta ballon injury was set up and the therapertic group was treated with SND. The shape of proliferative and apoptotic cell were investigated by electron microscope. Immunohistochemistry staining was performed using ?-actin,PCNA and Cyclin E monoclonal antibodies. In situ Cell Death Detection Kit was used to identify apoptotic cells. Abdomial aorta angiography was operated in the 84th day subgroup and the stenosis degree was evalued by quantitative angiographic analysis. RESULTS: As compared with the control group, the therapeutic group displayed a lower proliferative percentage and a higher apoptosic percentage (P