年龄对血管弹性和内皮细胞功能的影响

目的　本研究采用桡动脉脉搏波分析动脉弹性和激光多普勒血流测定方法评价增龄对内皮细胞功能的影响 ,阐明动脉弹性降低可以用于早期无创评估人的内皮细胞功能。方法　 2 4例无心血管疾病史的男性健康志愿者分为青年组 (年龄 2 0～ 30岁 ,n =12 )和老年组 (年龄 6 0～ 70岁 ,n=12 ) ,离子电渗透法向受试者前臂皮肤导入乙酰胆碱 (acethycholine ,Ach)和硝普钠 (sodiumnitroprusside,SNP) ,激光多普勒流量测定仪测量基础和峰值血流量 ;采用桡动脉脉搏分析法无创性评价大动脉弹性指数 (C1 )和小动脉弹性指数 (C2 )。结果　青年组和老年组的基础血流无明显差异 ,与青年组相比 ,Ach诱导的老年组峰值血流量明显减少 [( 83 4 0± 11 90 )比 ( 93 75± 10 87)PU ,P =0 0 3],而SNP诱导的峰值血流在两组间无明显差异 [( 119 17± 16 76 )比 ( 12 8 33± 2 1 2 9)PU ,P =NS];老年组与青年组比较 ,C1 和C2 明显降低 [C1 ( 11 4 2± 1 6 7)比 ( 16 75± 2 0 9)ml mmHg× 10 ,P <0 0 0 1;C2 ( 7 6 7± 1 5 6 )比 ( 10 75± 1 86 )ml mmHg× 10 0 ,P <0 0 0 1];动脉血管弹性的变化与Ach诱导的皮肤血流改变呈正相关 ,与SNP诱导的皮肤血流改变无关。结论　增龄导致动脉弹性降低和血管内皮功能损害 ,动脉弹性降低     

冠心病患者血管内皮功能障碍与动脉弹性关系的研究

目的　探讨冠心病患者血管内皮功能障碍与动脉弹性的关系。方法　采用高分辨率血管超声法检测 30例冠心病患者与 30例正常对照组肱动脉血流介导的内皮依赖性血管舒张功能(FMD);应用动脉弹性功能检测仪测定受试者的大动脉弹性指数 (C1 )和小动脉弹性指数 (C2 )。结果　冠心病组血流介导的肱动脉舒张反应明显低于对照组[ (5 17±2 13)% 与 (11 10±4 36)%,P<0 05];冠心病组与正常对照组的C1 差异无统计学意义 [ ( 11 59±4 56 )ml/mmHg( 1mmHg=0 133kPa) ×10与 (12 11±3 82)ml/mmHg×10, P>0 05],但冠心病组的C2 明显低于正常对照组[ (4 20±1 80)ml/mmHg×100与 (6 26±2 36)ml/mmHg×100, P<0 05],冠心病组血流介导的肱动脉舒张反应与C2 呈正相关(r=0 53, P<0 05)。结论　冠心病患者肱动脉内皮依赖血管舒张功能受损和C2 降低,且两者之间呈正相关,提示C2 可作为一种评价血管内皮功能的新指标。     

老年单纯收缩期高血压的动脉弹性功能变化

目的　比较老年正常血压者、单纯性收缩期高血压 (ISH)与非单纯性收缩期高血压 (NISH)患者的动脉弹性功能 ,了解不同类型老年高血压大动脉和小动脉弹性的差别。方法　选择 5 0例健康老年人 (男女各 2 5例 ,平均年龄 6 8± 5岁 )和 84例老年高血压病人 (男性 39例 ,女性 4 5例 ,平均年龄 6 8± 5岁 ) ,其中单纯性收缩期高血压 (ISH) 6 4例 ,非单纯性收缩期高血压 (NISH) 2 0例。使用DO2 0 2 0动脉功能测定仪检测桡动脉脉搏波形和动脉弹性指数C1和C2 。结果　ISH大动脉弹性指数C1(7± 2 1ml/mmHg× 10 )低于NISH组 (9 2± 3 1ml/mmHg× 10 )和正常血压对照组(12 9± 4ml/mmHg× 10 ) ,P <0 0 1;ISH小动脉弹性指数C2 (2 6± 2 2ml/mmHg× 10 0 )与NISH(2 7± 2 5ml/mmHg× 10 0 )无显著差别 ,均低于正常血压对照组 (4 3± 2 5ml/mmHg× 10 0 ) ,P <0 0 1;在正常血压对照组 ,动脉弹性指数与脉压显著负相关 (C1:r=- 0 6 2 7,P <0 0 0 1;C2 :r =- 0 389,P <0 0 0 1) ,但在ISH则并不相关 (C1:r =- 0 10 5 ,P =0 4 10 ;C2 :r =- 0 2 0 3,P =0 10 8)。结论　老年单纯性收缩期高血压患者大动脉和小动脉弹性功能均有明显减退     

高胆固醇对内皮祖细胞数量和功能的影响

目的　观察高胆固醇血症患者外周血内皮祖细胞 (EPC)数量和功能的变化。方法选择高胆固醇血症患者和非高胆固醇血症患者各 2 0例 ,用密度梯度离心法从外周血获取单个核细胞 ,将其接种在人纤维连接蛋白包被培养板 ,培养 7d后贴壁细胞进行细胞化学分析。激光共聚焦显微镜鉴定FITC UEA Ⅰ和DiI acLDL双染色阳性细胞为正在分化的EPC。采用MTT比色法、改良的Boyden小室和黏附能力测定实验观察EPC的增殖、迁移和黏附能力。结果　高胆固醇血症患者外周血EPC数量明显减少 [(41 8± 8 7比 6 4 5± 16 6 )EPCs/× 2 0 0视野 ,P <0 0 5 ],且EPC数量与血总胆固醇水平 (r =- 0 6 5 9,P <0 0 0 1)和低密度脂蛋白胆固醇水平 (r =- 0 6 11,P <0 0 0 1)呈反向线性关系。高胆固醇血症患者EPC的增殖、迁移和黏附能力也明显受损。结论　高胆固醇患者外周血内皮祖细胞数量减少、功能减退。     

中国健康人群动脉弹性功能参数研究

目的　建立中国健康人群男、女性和各年龄组大动脉弹性指数 (C1 )和小动脉弹性指数(C2 )的正常参照值 ,评价动脉弹性指数测定短期内的重复性。方法　选择中国 10个城市年龄 15～ 80岁正常血压健康人 192 4例 (男 947,女 977) ,采用动脉弹性功能测定仪CVProfilorDO 2 0 2 0 ,平卧位同步测量并记录 30s肱动脉血压和桡动脉脉搏波形 ,获取C1 和C2 。连续测定 3次 ,每次相隔 4min ,7～ 2 8d后进行重复性检测。结果　中国健康人群C1 和C2 平均值分别为 ( 16 0± 4 1)ml mmHg× 10、( 6 6±3 0 )ml mmHg× 10 0。女性C1 和C2 均低于男性 ,无论男、女性C1 和C2 均与年龄负相关。各地区C1 和C2 平均值的绝对差值较小。根据C1 和C2 与年龄的回归方程 ,已获得不同年龄组男、女性C1 和C2 的正常参照值范围。重复检测的数据较接近 ,尤其是C2 。结论　健康人群动脉弹性指数C1 和C2 受性别、年龄影响 ,应按照男、女性和不同年龄组建立其正常参照值。动脉弹性指数C1 和C2 测定在短期内有较好重复性。     

冠心病患者内皮祖细胞与动脉弹性相关性及缬沙坦干预研究

目的探讨冠状动脉粥样硬化性心脏病(coronary heart disease,CHD)患者内皮祖细胞(endothelial progenitor cell,EPCs)数量及动脉弹性指数之间的相关性,以及缬沙坦干预后EPCs水平和动脉弹性指数变化。方法冠状动脉造影检查确诊的冠心病患者60例为CHD组,同期排除冠心病的门诊健康体检者60例为对照组。两组患者采集外周血用密度梯度离心法获取单个核细胞,接种在人纤维连接蛋白包被的培养板,培养贴壁后进行细胞化学分析。激光共聚焦显微镜鉴定FITC-UEA-I和DiI-acLDL双染色阳性细胞为正在分化的EPC。进行EPCs水平测定。动脉弹性功能检测仪测定患者的大、小动脉弹性指数(C1、C2)。CHD组患者术后缬沙坦80mg/天干预12、24周后再次检测EPCs水平和动脉弹性指数。结果CHD组EPCs数量、C1、C2分别为32.8±6.4 EPCs/×200视野、9.82±1.54、3.67±0.87,对照组为61.6±9.5 EPCs/×200视野、15.3±2.52、7.51±2.03,两组差异有显著统计学意义(P<0.01);CHD组动脉弹性功能指数与EPCs水平呈正相关(r值分别为0.94、0.98,均P<0.01)。CHD组患者缬沙坦80mg/天干预12、24周后EPCs数量明显增加(37.7±7.98 vs 50.80±8.10,P<0.01),动脉弹性指数改善(C1:10.6±1.98 vs 12.55±2.43,C2:4.37±1.03 vs 5.77±1.99,均P<0.01),差异有显著统计学意义。结论CHD患者EPCs水平减低和动脉弹性指数下降是冠心病发病的独立危险因素之一,且两者之间呈正相关。CHD患者缬沙坦80mg/天干预12、24周后明显提高EPCs数量和动脉弹性指数。     

高甘油三酯血症对动脉弹性功能的影响

目的　研究高甘油三酯血症患者动脉弹性功能的变化。方法　采用动脉弹性功能测定仪CVProfilorDo -2 0 2 0检测 12例高甘油三酯血症患者和 15例健康志愿者大动脉弹性指数C1和小动脉弹性指数C2。结果　高甘油三酯血症患者和对照组的大动脉弹性指数C1无明显差别 (13 4± 3 6vs 14 3± 3 9ml/mmHg× 10 ) ,与对照组比较 ,高甘油三酯血症患者小动脉弹性指数C2明显降低 (6 3± 1 9vs 8 5± 2 4ml/mmHg× 10 0 ,P <0 0 5 )。结论　高甘油三酯血症损伤小动脉弹性指数C2 ,提示血管内皮细胞功能障碍可能是高甘油三酯血症导致冠心病发病和死率增加的原因之一     

老年单纯收缩期高血压的动脉弹性功能变化

目的比较老年正常血压者、单纯性收缩期高血压(ISH)与非单纯性收缩期高血压(NISH)患者的动脉弹性功能,了解不同类型老年高血压大动脉和小动脉弹性的差别.方法选择50例健康老年人(男女各25例,平均年龄68±5岁)和84例老年高血压病人(男性39例,女性45例,平均年龄68±5岁),其中单纯性收缩期高血压(ISH)64例,非单纯性收缩期高血压(NISH)20例.使用DO2020动脉功能测定仪检测桡动脉脉搏波形和动脉弹性指数C1和C2.结果 ISH大动脉弹性指数C1(7±2.1 ml/mmHg×10)低于NISH组(9.2±3.1 ml/mmHg×10)和正常血压对照组(12.9±4 ml/mmHg×10),P＜0.01;ISH小动脉弹性指数C2(2.6±2.2 ml/mmHg×100)与NISH(2.7±2.5 ml/mmHg×100)无显著差别,均低于正常血压对照组(4.3±2.5 ml/mmHg×100),P＜0.01;在正常血压对照组,动脉弹性指数与脉压显著负相关(C1 r=-0.627, P＜0.001; C2 r=-0.389, P＜0.001),但在ISH则并不相关(C1 r=-0.105, P=0.410; C2 r=-0.203, P=0.108).结论老年单纯性收缩期高血压患者大动脉和小动脉弹性功能均有明显减退.     

降压治疗对高血压患者动脉弹性功能的影响

目的　观察降压治疗对动脉弹性功能的影响。方法　选择 6 0例高血压病人 (高血压控制组与高血压未控制组各 30例 )和 30例正常对照组 ,使用DO2 0 2 0动脉功能测定仪检测大动脉弹性指数C1和小动脉弹性指数C2。结果　高血压控制组的C1(10 70± 3 71ml/mmHg× 10 )和C2(3 98± 2 0 9ml/mmHg× 10 0 )均明显高于高血压未控制组C1(7 96± 3 0 1ml/mmag× 10 )和C2 (2 5 0± 1 14ml/mmHg× 10 0 ) (P <0 0 5 ) ,高血压控制组的C1与对照组C1(11 4 2± 1 6 7ml/mmHg× 10 )无显著差别 (P >0 0 5 ) ,但C2低于正常对照组C2 (7 6 7± 1 5 6ml/mmHg× 10 0 ) (P <0 0 5 )。结论　降压治疗能改善高血压患者大动脉和小动脉弹性功能     

基质细胞衍生因子1α介导小鼠内皮祖细胞修复损伤血管内膜

目的探讨损伤血管局部表达的基质细胞衍生因子1α是否能介导内皮祖细胞参与损伤血管的再内皮化,抑制新生内膜的增生。方法培养、获取小鼠骨髓源性内皮祖细胞,采用改良的Boyden小室测定基质细胞衍生因子1α诱导的内皮祖细胞迁移及AMD3100(CXCR4的拮抗剂)对其的影响。分别将内皮祖细胞培养基、内皮祖细胞及AMD3100孵育过的内皮祖细胞经心脏穿刺注射给颈动脉损伤小鼠,在14天后取损伤血管检测内皮祖细胞募集情况、再内皮化情况及新生内膜增生情况。结果基质细胞衍生因子1α能诱导内皮祖细胞迁移(与对照组比较P<0.01),AMD3100能有效阻断该作用(AMD3100组与对照组比较P>0.05)。较多注射的内皮祖细胞成功归巢到损伤血管处(14.2±3.6个/切片),AMD3100孵育过的内皮祖细胞仅少量可成功归巢(4.0±2.5个/切片);内皮祖细胞注射能加速损伤血管的再内皮化(内皮祖细胞移植组比对照组:83.45%±5.44%比66.46%±6.16%,P<0.01),AMD3100孵育过的内皮祖细胞注射则无效(68.02%±6.68%,与对照组比较P>0.05);内皮祖细胞移植组新生内膜增生厚度(19237±1875μm2)和内膜中膜比值(0.94±0.12)均小于对照组(34676±2412μm2和1.77±0.18)及AMD3100组(32451±2081μm2和1.60±0.17)(P<0.01)。结论基质细胞衍生因子1/CXCR-4在介导移植的内皮祖细胞修复损伤血管内膜中起重要作用。     

Circulating endothelial progenitor cell deficiency contributes to impaired arterial elasticity in persons of advancing age

Reduced arterial elasticity is a hallmark of ageing in healthy humans and appears to occur independently of coexisting disease processes. Endothelial-cell injury and dysfunction may be responsible for this fall in arterial elasticity. We hypothesized that circulating endothelial progenitor cells (EPCs) are involved in endothelial repair and that lack of EPCs contributes to impaired arterial elasticity. A total of 56 healthy male volunteers were divided into young (n=26) and elderly (n=30) groups. Large and small artery elasticity indices were noninvasively assessed using pulse wave analysis. The number of circulating EPCs was measured by using flow cytometry. Cells demonstrating DiI-acLDL and FITC-ulex lectin double-positive fluorescence were identified as EPCs. C1 large artery elasticity and C2 small artery elasticity indices were significantly reduced in the elderly group compared with the young group (11.73+/-1.45 vs 16.88+/-1.69 ml/mm Hg x 10, P<0.001; 8.40+/-1.45 vs 10.58+/-1.18 ml/mm Hg x 100, P<0.001, respectively). In parallel, the number of circulating EPCs was significantly reduced in the elderly group compared with the young group (0.13+/-0.02 vs 0.17+/-0.04%, P<0.05). The number of circulating EPCs correlated with C1 large and C2 small artery elasticity indices (r=0.47, P<0.01; r=0.4, P<0.01). The present findings suggest that the fall in circulating EPCs with subsequently impaired endothelial-cell repair and function contributes to reduced arterial elasticity in humans with ageing. The decrease in circulating EPCs may serve as a surrogate biologic measure of vascular function and human age.     

Reduced arterial elasticity is associated with endothelial dysfunction in persons of advancing age: comparative study of noninvasive pulse wave analysis and laser Doppler blood flow measurement

BACKGROUND: Endothelial dysfunction is the earliest marker for age-related abnormalities in vascular function, and examination of endothelial function has important clinical relevance. The present study was performed to evaluate effects of aging on arterial elasticity by using pulse waveform analysis and to investigate whether the changes in arterial elasticity might be used as a noninvasive measure for endothelial dysfunction. METHODS: A total of 24 healthy male volunteers were divided into young (n = 12) and elderly (n = 12) groups. Endothelial function was evaluated by delivering acetylcholine (Ach) and sodium nitroprusside (SNP) to the forearm vessels using iontophoresis, respectively, and measured blood flow using laser Doppler fluximetry. Large and small artery elasticity indices were noninvasively assessed using pulse wave analysis. RESULTS: Basal blood flow was similar between the young and elderly groups (14.58 +/- 3.4 v 13.52 +/- 3.41 PU, P = NS). Peak blood flow induced by Ach was significantly reduced in the elderly group compared with the young group (83.4 +/- 11.9 v 93.75 +/- 10.87 PU, P < .05). However, peak blood flow induced by SNP was similar in the two groups (119.17 +/- 16.76 v 128.33 +/- 21.29 PU, P = NS). In parallel, C1 large artery elasticity and C2 small artery elasticity indices were significantly reduced in the elderly group compared with the young group (11.42 +/- 1.67 v 16.75 +/- 2.09 mL/mm Hg x 10, P < .001; and 7.67 +/- 1.56 v 10.75 +/- 1.86 mL/mm Hg x 100, P < .001, respectively). The Ach-induced peak blood flow correlated with C1 large and C2 small artery elasticity indices. CONCLUSIONS: Advancing age is associated with endothelial dysfunction and reduced arterial elasticity. Reduced arterial elasticity parallels changes in impaired endothelium dependent vasodilation. It appears that reduced arterial elasticity may be used as a noninvasive measure for the determination of endothelial function.     

Berberine-induced mobilization of circulating endothelial progenitor cells improves human small artery elasticity

Berberine (BR) has been proved to promote endothelial function. However, the exact mechanisms underlying the effect of BR on endothelial function are not completely clear. It has been demonstrated that endothelial progenitor cells (EPCs) contribute to improvement of endothelial function and C2 small artery elasticity index is a surrogate parameter for the clinical evaluation of endothelial function. We hypothesized that BR-induced mobilization of circulating EPCs is associated with BR-related improvement of endothelial function. To address this assumption, 15 healthy volunteers were recruited and received BR 0.4 g three times per day for 30 days. The number of circulating CD34/KDR double-positive cells as well as C1 large and C2 small artery elasticity indices were evaluated before and after BR therapy. The number of CD34/KDR double-positive EPCs increased significantly after BR treatment (0.030+/-0.020% vs 0.017+/-0.010%, P<0.01). After 30-day BR therapy C2 increased significantly (6.21+/-2.80 ml per mm Hg x 100 vs 4.06+/-2.67 ml per mm Hg x 100, P<0.01) and C1 remained unchanged (10.79+/-3.27 ml per mm Hg x 10 vs 10.06+/-2.08 ml per mm Hg x 10, P>0.05). The increment of CD34/KDR double-positive EPCs was positively correlated with the increment of C2 (r=0.68, P<0.01). We concluded that BR-induced mobilization of circulating EPCs contributes to improvement of small artery elasticity in healthy persons.     

冠心病患者胰岛素水平与内皮祖细胞及冠状动脉病变的相关性

目的 探讨冠心病患者不同胰岛素水平与循环内皮祖细胞(EPC)数量、功能及冠状动脉病变程度的关系并探讨相关临床意义.方法 69例经选择性冠状动脉造影证实的冠心病患者,按胰岛素水平高低分为胰岛素抵抗(IR)组和胰岛素敏感(IS)组,另设25例健康对照者.采集研究对象外周血以激酶插入区域受体(KDR)和CD133双阳性为循环EPC标记行流式细胞分析,同时采血进行EPC的分离培养,7 d后鉴定并检测增殖及迁移能力,将各组的一般临床资料,循环EPC数量、迁移、增殖能力指标、稳态模型胰岛素抵抗指数(HOMA-IR)及冠状动脉病变Gensini评分进行统计学分析.结果 IR组循环EPC数量明显少于IS组[(0.34±0.08)‰比(0.47±0.09)‰,P<0.01],HOMA-IR自然对数与循环EPC数量呈负相关(r=-0.291,P=0.01),循环EPC数量与Gensini评分呈负相关(r=-0.3984,P=0.006).IR组的增殖能力和迁移能力均低于IS组减弱(P<0.05).结论 冠心病患者血清胰岛素水平与循环EPC数量呈负相关.循环EPC数量及功能与冠状动脉病变程度呈负相关;IR或高胰岛素血症可能部分通过损害循环EPC的数量及功能,从而影响冠状动脉病变程度.     

Impaired endothelial progenitor cell activity is associated with reduced arterial elasticity in patients with essential hypertension

Endothelial dysfunction is related to reduced arterial elasticity in patients with essential hypertension. Circulating endothelial progenitor cells (EPCs), an important endogenous repair approach for endothelial injury, is altered in hypertensive patients. However, the association between alteration in circulating EPCs and hypertension-related reduced arterial elasticity has not been reported. The purpose of this study is to investigate the association between alteration in circulating EPCs and hypertension-related reduced arterial elasticity. We measured the artery elasticity profiles including brachial-ankle PWV (baPWV) and C1 large and C2 small artery elasticity indices in patients with essential hypertension (n = 20) and age-matched normotensive subjects (n = 21). The number and activity of circulating EPCs isolated from peripheral blood were determined. Compared to normotensive subjects, the patients with hypertension exhibited decreased C1 large and C2 small artery elasticity indices, as well as increased baPWV. The number of circulating EPCs did not differ between the two groups. The migratory and proliferative activities of circulating EPCs in hypertensive patients were lower than those in normotensive subjects. Both proliferatory and migratory activities of circulating EPCs closely correlated with arterial elasticity profiles, including baPWV and C1 large and C2 small artery elasticity indices. Multivariate analysis identified both proliferative and migratory activities of circulating EPCs as independent predictors of the artery elasticity profiles. The present study demonstrates for the first time that impaired activity of circulating EPCs is associated with reduced arterial elasticity in patients with hypertension. The fall in endogenous repair capacity of vascular endothelium may be involved in the pathogenesis of hypertension-related vascular injury.     

不稳定性心绞痛患者循环内皮祖细胞与血管内皮功能的变化

目的探讨不稳定性心绞痛患者外周血循环内皮祖细胞(EPCS)与血管内皮功能的变化。方法采用高分辨率血管超声法检测30例不稳定性心绞痛患者与30例正常者作对照组肱动脉血流介导的内皮依赖性血管舒张功能(FMD)及硝酸甘油介导的非内皮依赖性血管舒张功能(NMD);流式细胞仪测定外周血中CD34+单个核细胞的水平;外周血分离单个核细胞一定条件下培养2周,免疫组织化学技术鉴定培养贴壁细胞表面标志CD34的表达;倒置荧光显微镜鉴定贴壁细胞FITC-UEA-I和DII-ACLDL双染色阳性细胞为正在分化的EPCS。结果不稳定性心绞痛组FMD明显低于对照组[(5·85±3·04)%比(8·81±4·48)%,P<0·05];NMD在两组中差异无统计学意义[(13·60±5·03)%比(14·18±4·50)%,P>0·05];CD34+细胞水平明显高于对照组[(0·13±0·05)%比(0·09±0·04)%,P<0·05];FMD与CD34+细胞水平呈负相关(R=-0·385,P<0·05)。培养的贴壁细胞免疫组化显示CD34阳性,倒置荧光显微镜显示这些贴壁细胞FITC-UEA-I和DII-ACLDL双染色阳性。结论不稳定性心绞痛患者CD34+细胞增加和血管内皮功能受损,提示循环EPCS增加可能是对急性冠状动脉缺血和内皮损伤的代偿反应。     

老年心肌梗死患者循环血内皮祖细胞数目和功能的变化及其对心功能的影响

目的 比较不同年龄组心肌梗死患者循环血内皮祖细胞（EPCs）数目及功能的差异,分析蛋白激酶B（Akt）和间质细胞源因子1（SDF-1）表达的差异,探讨老年患者EPCs修复梗死心脏功能的可能机制及临床意义.方法 抽取老年心肌梗死患者（n=26）和中青年心肌梗死患者（n=24）动脉血8 ～10 ml,流式细胞仪检测各组EPCs含量,酶联免疫吸附法检测Akt及SDF-1表达变化情况;利用冠状动脉左前降支结扎术制备大鼠心肌梗死模型后,尾静脉注射老年EPCs、中青年EPCs（1×107/200 ml）或等体积盐水（PBS组）,观察终点时间为28 d,超声心动评价心脏功能,荧光显微镜下观察EPCs在梗死心脏的归巢情况,免疫荧光法计数缺血心肌局部血管数量.结果 老年心肌梗死患者循环血EPCs数量明显少于中青年组（47.23％±14.92％比89.76％ ±7.27％,P＜0.001）;心肌梗死后老年组Akt磷酸化水平和SDF-1表达水平明显低于中青年组（Akt：19.04％±6.41％比43.96％±15.91％;SDF-1：25.81％ ±6.32％比64.04％±16.35％,均为P＜0.001）.将EPCs移植至梗死大鼠后,移植的老年EPCs在梗死心脏的归巢数量明显少于移植的中青年EPCs（3.69±1.97/mm2比12.01 ±5.44/mm2,P ＜0.001）.移植老年EPCs的大鼠梗死心脏的血管密度明显少于移植中青年EPCs的大鼠（42±9/mm2 比96±15/mm2,P ＜0.001）.移植老年EPCs组心功能指标[左心室射血分数（LVEF）和左心室缩短分数（LVFS）]显著低于移植中青年EPCs组（LVEF：58.1％±5.0％比73.8％±7.9％;LVFS：35.4％±3.8％比59.0％±7.6％.均为P＜0.001）.结论 老年心肌梗死患者的循环血EPCs数量及其修复功能均不如中青年患者,可能与Akt-SDF-1信号通路受损有关.     

Effect of green tea consumption on endothelial function and circulating endothelial progenitor cells in chronic smokers.

BACKGROUND: The present study was designed to investigate the effect and relationship of endothelial function and endothelial progenitor cells (EPCs) by green tea consumption in chronic smokers. The numbers of circulating EPCs have an inverse correlation with chronic smoking and endothelial dysfunction. Green tea catechin improved endothelial dysfunction in chronic smokers. METHOD AND RESULTS: In 20 young healthy smokers, endothelial functions, defined by flow-mediated endothelium dependent vasodilation (FMD) of the brachial artery via ultrasound as well as the number of EPCs isolated from peripheral blood, were determined at baseline and at 2 weeks after green tea consumption (8 g/day). Circulating EPCs were quantified by flow cytometry as CD45lowCD34+KDR2+ cells and by acyl-low-density lipoprotein and fluorescein isotiocyanate-lectin double positive cells after culture for 7 days. Clinical characteristics and laboratory findings were not significantly different between the baseline and at 2 weeks after green tea intake. EPC levels were inversely correlated with the number of cigarettes smoked. Circulating EPCs by flow cytometry (78.6+/-72.6 vs 156.1+/-135.8 /ml, p<0.001) and cultured EPCs (118.2+/-35.7 vs 169.31+/-58.3/10 field, p<0.001) increased rapidly at 2 weeks after green tea consumption. FMD was significantly improved after 2 weeks (7.2+/-2.8 vs 9.3+/-2.4, p<0.001). The FMD correlated with EPC counts (r=0.67, p=0.003) before treatment and after 2 weeks (r=0.60, p=0.013). CONCLUSIONS: A short-term administration of green tea consumption induces a rapid improvement of EPC levels and FMD. Green tea consumption may be effective to prevent future cardiovascular events in chronic smokers.