摘要目的 了解高脂饮食对载脂蛋白(apoE)缺乏鼠(apoE-/-)维生素D受体(VDR)表达及内皮型一氧化氮合酶(eNOS)活性影响,探讨VDR在动脉粥样硬化(AS)形成的意义及可能机制.方法 apoE-/-小鼠与作为对照的C57BLP6J小鼠分别按数字表法分为正常食物组与高脂食物组,采用竞争蛋白结合放射免疫法检测小鼠血25-(OH)D水平,采用免疫荧光化学法及RT-PCR法检测小鼠主动脉VDR表达,应用硝酸还原酶法检测小鼠血一氧化氮(NO)含量和eNOS酶活力.结果 高脂饮食进一步加重apoE-/-小鼠AS病变、降低血25-(OH)D水平[血25-(OH)D:正常饲料C57BLP6J小鼠、高脂饲料C57BLP6J小鼠、正常饲料apoE-/-小鼠、高脂饲料apoE-/-小鼠分别为[(26.44±1.28)ng/mL、(22.68±2.07)ng/mL、(17.46±2.22)ng/mL、(15.88±0.97)ng/mL,P＜0.01].高脂饮食进一步上调apoE-/-小鼠主动脉VDR蛋白与mRNA表达水平[VDR蛋白分别为0.244±0.088、0.346±0.132、0.547±0.128、0.768±0.162,VDRmRNA分别为0.228±0.083、0.375±0.103、0.451±0.117、0.597±0.131,P均＜0.01].高脂饮食致apoE-/-小鼠血NO水平、eNOS酶活力明显增高[NO:(39.74±4.81)μmol/L、(48.1±5.24)μmol/L、(67.34±6.14)μmol/L、(86.74±8.05)μmol/L;eNOS:(8.6±0.77)U/L、(12.28±1.42)U/L、(15.96±0.92)U/L、(18.68±1.15)U/L,P均＜0.01].血25-(OH)D水平与血浆中NO含量、eNOS酶活力及VDR表达呈负相关(P＜0.01).结论 apoE-/-小鼠血25-(OH)D水平降低,VDR表达量明显上调,血NO含量、eNOS酶活力增高,高脂饮食可进一步降低血25-(OH)D、NO水平,上调主动脉VDR表达,增加eNOS酶活力.高脂饮食、维生素D、apoE相互作用,影响AS病变可能与NO、eNOS有关.

abstractsObjective This study investigated high fat diet influence on the changes of vitamin D receptor (VDR) expression and endothelial nitric oxide synthase (eNOS) in apolipoprotein E-deficient(apoE-/-) mice.Methods ApoE-/- mice and C57BLP6J mice were divide into two groups (normal control and high fat diet),high fat diet group were feed high fat feedstuff.Plasma 25-(OH)D levels were determined by competitive protein binding radioimmunity,VDR expression were determined by immunofluorescence and reverse transcription-polymerase chain reaction.The levels of NO and eNOS were determined by nitrate reductase.Results Compared with normal control group,high fat diet caused more severe dam-age of atherosclerosis in wild type mice and apoE-/- mice.In apoE-/- mice,the levels of plasma 25-(OH)D were significantly decreased [(26.44±1.28) ng/mL,(22.68±2.07)ng/mL,(17.46±2.22)ng/mL,(15.88±0.97)ng/mL,P＜0.01],the expression of VDR protein and mRNA were significantly increased[VDR :0.244±0.088,0.346±0.132,0.547±0.128,0.768±0.162;VDRmRNA:0.228±0.083,0.375±0.103,0.451±0.117,0.597±0.131,P＜0.01],and the levels of NO and eNOS were significantly increased[NO:(39.74±4.81)μmol/L,(48.1±5.24 )μmol/L,(67.34±6.14 )μmol/L,(86.74±8.05)μmol/L;eNOS:(8.6±0.77 )U/L,(12.28±1.42)U/L,(15.96±0.92)U/L,(18.68±1.15)U/L,P＜0.01].These changes were more significantly in high fat diet group(P＜0.01).Conclusions There were abnormalities of plasma 25-(OH)D level,VDR expression and the level of NO and eNOS in apoE-/- mice.These changes were more significantly in high fat diet group.