AIM: To examine the effect of pretreatment with low-concentration of 11, 12-epoxyeicosatrienoic acid(EET) on myocardial ischemia/reperfusion injury in rats. METHODS: After tracheotomy, myocardial ischemia/reperfusion was produced by occlusion and release of the left anterior descending artery(LAD) of the rats. Ischemic preconditioning(IP) was made by two times of ischemia (5 min)/reperfusion (5 min). The experiment was conducted in three groups: control,IP and pretreatment with 11,12-EET(6.24?10 -8 mol/L), and each group was subdivided into two subgroups:A,the rats were subjected to ischemia (10 min)/reperfusion (10 min) and arrhythmias during the whole periods were monitored; The rats in B were subjected to ischemia (60 min)/reperfusion (30 min) and arrhythmias, cardiac funtion and myocardial infarction size were documented. RESULTS: Both IP and pretreatment with 11,12-EET could protect the heart against arrhythmias, cardiac disfunction and myocardial infarction. CONCLUSION: Pretreatment with 11,12-EET had protective effect on myocardium in case of ischemia/reperfusion, which was similar to ischemic preconditioning.

AIM: In order to study the relationship between the ERK and p38 MAPK activation and the protection of 11, 12-epoxyeicosatrienoic acid (11, 12-EET) and ischemia preconditioning (IP), the effects of 11, 12-EET and ischemic preconditioning on phosphorylated ERK and p38 MAPK during ischemia and reperfusion in rat myocardium were examined. METHODS: The rat heart was subjected to ischemia for 5 min by ligating the left anterior descending coronary artery followed by reperfusion for 5 min (two times) to undergo ischemia preconditioning. The rats were divided into 5 groups: (1) control; (2) sham group; (3) ischemia/reperfusion (I/R) group, in which the rat heart suffered from 60 min ischemia followed by 30 min reperfusion; (4) IP plus I/R group; (5) EET plus I/R group, in which 6.28?10 -8 mol/L 11, 12-EET was injected intravenously 20 min before I/R. The heart function was examined, and phosphorylated ERK and p38 MAPK were detected by Western blot. RESULTS: At 30 min reperfusion, +dp/dt max ,-dp/dt max and LVDP decreased significantly in I/R group compared with sham group, IP plus I/R group and EET plus I/R group; Phosphorylated ERK1/2 level was higher in I/R group than sham group, but was lower in I/R group than IP plus I/R group and EET plus I/R group; Phosphorylated p38 MAPK level was lower in control, sham, IP plus I/R and EET plus I/R group than I/R group. CONCLUSION: 11,12-EET protects rat heart against ischemia/reperfusion injury, the mechanism may be related to activation of ERK1/2 and inhibition of p38 MAPK. [

AIM: To study the influence of PD098059 on the rat platelet aggregation rate and the phosphorylation of ERK1/2 induced by the different agonists, and to observe the effects of phosphorylation of ERK1/2 on the platelet aggregation. METHODS: The maximal aggregation rate (MAR) was measured by nephelometry. The inhibitory rate of PD098059 and the appearing time of MAR were also observed. ERK1/2 phosphorylation was detected by Western blot. RESULTS: The phosphorylation of ERK1/2 was detected during aggregation induced by thrombin and ADP. PD098059 inhibited the MAR and phosphorylation of ERK1/2. Effects of PD098059 were different on the aggregation induced by thrombin and ADP. CONCLUSIONS: The phosphorylation of ERK1/2 is one of the cellular signal transduction mechanisms of platelets aggregation. Phosphorylation of ERK1/2 plays different roles during the platelet aggregation induced by thrombin and ADP. [

Designed experiment in medical functional experiment has become an important way to promote creative thinking and innovation of medical students.We applied different modes of designed experiment in undergraduates of clinical medicine and basic medicine in capital medical university,including classroom designed experiments,proposition designed experiments and free proposition designed experiments.After above reforming implements,creative thinking and innovation ability of medical students were enhanced.It also provided new ideas in future teaching reform in functional experiment.

Aim To investigate the expression of phosphorylated JNK1/JNK2 and the protection of 11,12-EET in ischemic and reperfusion rat heart.Method The expression of JNK1/JNK2 was detected with western blot method and the changing of heart function during ischemia/reperfusion process was observed in different groups. Results The cardiac function (+dp/dt_(max)%,-dp/dt_(max)% and LVDP)of reperfusion periods(30 min) apparently decreased in ischemia/reperfusion (I/R) group contrasted with Sham group, short ischemia(SI)+I/R group and EET+I/R group,and the expression of phosphorylated JNK1/JNK2 increased in I/R group contrasted with nromal group,Sham group and EET+I/R group.Conclusion The myocardial protection of 11,12-EET ( 6.24?10~(-8) mol?L~(-1)) is able to inhibit the expression of phosphorylated JNK1/JNK2.

Objective To detect CYP2J3 gene expression and contents of 11,12-EET in heart,liver,lung,kidney and aorta thoracalis after CYP2J3 gene transfection.Methods The rat transgenic model was developed by injecting plasmid through vena dorsalis penis.The animals were divided into control group、 pcDNA3.1 transgenic group and pcDNA3.1-CYP2J3 transgenic group.The expression of CYP2J3 mRNA was detected by RT-PCR and content of 11,12-EET was examined by the HPLC at 14 days and 28 days after injection.Results Twenty eight days after injection,both expression of CYP2J3 mRNA and the content of 11,12-EET were significantly increased as compared with that of control and pcDNA3.1 transgenic group(P

AIM: In order to study the relationship of the activation of ERK and delayed cardioprotection of 11,12-EET.METHODS: A rat ischemia/reperfusion(I/R) model was replicated by ligating left anterior descending coronary artery 30 min followed by 60 min.The expression of ERK was detected with Western blotting,and the change of heart function during reperfusion was observed.RESULTS: The difference of myocardial function was prominent at (24 h) in I/R group compared with sham group,EET+I/R and EET+PD098059+I/R group.The activity of ERK at(24 h) in EET+I/R group was higher than sham group, and the activity of ERK in EET+PD098059+I/R group was lower than that in EET+(I/R) group;the expression of phosphorylated ERK1/ERK2 at(24 h) in EET+I/R group was more than that in I/R group,and the expression of phosphorylated ERK1/ERK2 in EET+PD098059+I/R group was less than EET+I/R group.CONCLUSION: 11,12-EET has a delayed cardioprotection effect,and this protection effect is involved in the activity of ERK and expression of phosphorylated ERK1/ERK2.

AIM: To test the effect of ERK1/2 on ischemic preconditioning (IPC) in diabetic rat hearts. METHODS: The diabetic rat model was made with alloxan. After eight weeks, 24 rats were divided into 4 groups: non-diabetic IPC rats (group A); non-diabetic non-IPC rats (group B); diabetic IPC rats (group C); diabetic non-IPC rats (group D). ECGⅡ lead, left ventricular development pressure (LVDP), and first derivative of LVDP ~(?dp/dt_~max ) were recorded. Myocardial phosphorylation of extracellular signal regulated kinases1/2 (ERK1/2) was detected by Western-blotting. RESULTS: (1) The ventricular arrythmia score was significantly lower in group A than that in group C (P

In the pathophysiology experiment teaching,by combining the teaching of prob-lem-based learning with local area network(LAN) teaching,students first carry out a simple ex-periment to ask a question on the observed phenomenon,and then put forward a hypothesis,de-sign experiments to answer questions,and implement the experiment,and finally present experi-mental results.Such experimental design teaching is not only a great way to mobilize the stu-dents’interest in scientific research and learning initiative,but also greatly enhances the effi-ciency of the experiment.Students preliminarily master the basic scientific research program and methods.

OBJECTIVETo optimize the dynamic extraction process of salvianolic acids.

METHODSalvianolic acids was selected as index. The effects of extraction temperature, granularity, solvent multiple, circle value and extraction time were studied on the process of dynamical extraction. The orthogonal experiment was employed to investigate the influence of different parameters.

RESULTThe optimal extracting method of salvianolic acids was as follows: temperature was 80 degrees C, granularity was 4 mm, circle value was 30 L x h(-1), solvent multiple was 10 times and extraction time was 150 min.

CONCLUSIONBy comparison to static extraction, dynamic extraction can improve the extraction efficiency, reduce the solvent and energy consumption, as well as lower the burden of post-processing.