| Objective:1.To investigate the expression of stromal cell derived factor1（SDF-1) andit’s receptor CXCR4in the macro-vascular of diabetic rats with valvuloplasty;2.To investigate the effect of sitagliptin on the expression of SDF-1/CXCR4in the macro-vascular of diabetic rats with valvuloplasty.Methods:32healthy5-years old male sprague-dawlry(SD) rats were chosen,whose weights were between180and220g. They were divided into two groups:the normal control group (NC,n=8)were fed with basis forage and the model groupwere fed with high sucrose-fat diets. Four weeks later, after24h of ambrosia, asmall dose of streptozotocin (STZ,30mg/kg) was injected intraperitoneally onceinto the model group, while the normal group was injected with equivalent dose ofcitrate buffer.72h later, the tail vein blood sugar was measured in the next threedays. The groups whose glucose was higher than16.7mmol/L would be taken asthe successful diabetic rat model. The rats of the model group were divided intothree groups randomly: DM group (Diabetes Control group,which were under nointervened, n=6),S1group (sitagliptin-intervened group1,1mg/kg,n=8), S2group(sitagliptin-intervened group2,10mg/kg,n=8). Group S1and group S2wereirrigated with sitagliptin by infusing stomach at9:AM daily, while group NC andgroup DM were given the same dose of Sodium Chloride. The body weight (BW)was measured10weeks later. Then they were sacrificed to get the blood and aortaafter they were anesthetized and we needed to measure FBG,FINS,TG,TC, LDL-C,HDL-C after all the rats were sacrificed. One part of aorta was used to beobserved through the method of light microscopy after hematoxylin-eosin (HE)staining. The expression of SDF-1and CXCR4protein of the thoracic aorta weredetected by immunohistochemistry and their mRNA were detected by reverse transcriptase-polymerase chain reaction（RT-PCR).Results:1.Four weeks later, a comparison was made between each groups in theirbloodbiochemical and weight indicators: BW, FBG, TG,LDL-C,FINS, HOMA-IRin the model group DM were significantly higher than those of the groupNC(P<0.05),but the HDL-C,TC in this two groups was no statistically significant(P>0.05).2. Fourteen weeks later, the weight and blood index were measured: theweight of DM,S1,S2were lower than those of group NC(P<0.05). There were nodifferences between group DM and group S1,S2. The leve of TG,TC and LDL-Cof group DM,S1,S2were higher than those of group NC(P<0.05), while the leversof HDL-C,FINS were much lower,The difference was statistically significant(P<0.05).Compared with group NC, FBG in group DM,S1and S2was significanthigher(P<0.05).FBG in Group S2was lower than group DM(P<0.05),and FBG inGroup S1and group DM had no statistically significant (P>0.05).3.Fourteen weeks later, hematoxylin-eosin staining: Some of the aortaendotheliocyte had been damaged in the group DM, elastic fibre and disorderarrangement appear,some foam cells were visible.There was no pathological changein group NC, the aorta pathological of group S1and group S2change alleviatedwhen they were compared with group DM, furthermore, it demonstrated asignificant improvement in group S2compared with group S1.4. SDF-1and CXCR4Staining: There was little expression of SDF-1andCXCR4in group NC,the expression of SDF-1and CXCR4in group DM wereincreased remarkably compared with group NC, the comparison between groupDM and the two groups(S1,S2), and the comparison between S1and S2werestatistically significant (P<0.05).5. Reverse transcriptase-polymerase chain reaction (RT-PCR)showed thatthere were litter expression of SDF-1and CXCR4mRNA in group NC,the leversof group DM were higher than those of group NC,group S1and group S2.The levers of SDF-1and CXCR4mRNA in Group S2was significantly lower thangroup S1. There was little expression in group NC.Conclusions:1.The expression of SDF-1and CXCR4in the Diabetic rats which wereinduced by STZ is increase, This suggests that SDF-1and CXCR4are relate tomacroangiopathy.2. Sitagliptin can down-regulate the expression of SDF-1and CXCR4in theaorta of diabetic rats, improve the pathological change of diabetic rats’ aorta. |
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