二氢丹参酮Ⅰ灌胃对急性缺血性脑卒中大鼠神经功能改善作用及其机制

目的 探讨二氢丹参酮Ⅰ（DT）灌胃对急性缺血性脑卒中大鼠神经功能的改善作用及其机制。方法 将50只SD大鼠随机分为假手术组、模型组以及DT低、中、高剂量组。采用线栓法制备大鼠MCAO模型，假手术组仅分离血管，不进行插栓处理。造模后24 h,DT低、中、高剂量组分别给予1.67、5、15 mg/kg DT溶液灌胃，假手术组和模型组给予等量含2%DMSO的生理盐水灌胃，每天1次，连续7 d。造模24 h后和给药7 d后，采用Zea-Longa五分制评分法对大鼠进行神经行为学评分；采用TTC染色测算脑梗死体积；造模后和给药7 d后使用激光散斑血流仪检测大鼠缺血侧局部脑血流灌注量；HE染色观察缺血侧脑组织海马区的病理形态；Western blotting法检测缺血侧脑组织血管新生相关蛋白血管内皮生成因子（VEGF）、CD31、缺氧诱导因子1α(HIF-1α)表达。结果 模型组大鼠神经行为学评分及脑梗死体积大于假手术组（P均<0.01），缺血侧脑血流灌注量变化率低于假手术组（P<0.01）；与模型组比较，DT中、高剂量给药组神经行为学评分降低，脑梗死体积减小，缺血侧脑血流灌注量增加（...     

曲美他嗪后处理对心肌缺血再灌注损伤大鼠细胞凋亡的保护性作用

目的研究曲美他嗪后处理对大鼠急性心肌缺血再灌注损伤后细胞凋亡的影响。方法实验大鼠40只,随机分为5组：假手术组（n＝8）、再灌注损伤模型组（n＝8）、曲美他嗪低剂量组（10mg/kg,n＝8）、曲美他嗪高剂量组（20mg/kg, n＝8）,后处理组（n＝8）。制作再灌注损伤模型后,观察各组大鼠心肌梗死面积、Bcl2/bax蛋白表达以及电子显微镜下心肌组织切片观察。结果（1）各组大鼠心肌梗死面积测定：假手术组未见梗死,其余各组大鼠心肌组织不同程度梗死,以后处理组及曲美他嗪高剂量组最轻,差异具有统计学意义（P＜0.01）。（2）各组大鼠Bcl2/Bax蛋白表达比较：在模型组中Bax蛋白强阳性表达,表现为软件分析结果灰度值最低。而曲美他嗪高剂量组及后处理组灰度值较模型组比较灰度值明显增大（P＜0.01）。Bcl2蛋白在模型组中表达较少,在曲美他嗪高剂量组中及后处理组中明显表达,且差异具有统计学意义（P＜0.01）。（3）电子显微镜下观察：除假手术组大鼠外,各组大鼠均有不同程度损伤及细胞凋亡,后处理组及曲美他嗪高剂量组损伤较轻。结论高剂量曲美他嗪（20mg/kg）对大鼠心肌缺血再灌注损伤后细胞凋亡有抑制作用。     

虾青素对异丙肾上腺素诱导的大鼠心肌纤维化的影响

目的 探讨虾青素对异丙肾上腺素（ISO）诱导的大鼠心肌纤维化的影响。方法 SD大鼠腹腔注射异丙肾上腺素（5mg/kg/d），连续注射14d，建立心肌纤维化模型，从造模第二天开始给予虾青素（5mg/kg/d和10mg/kg/d）灌胃，连续21天。实验结束后超声心动图检测大鼠心脏功能，计算心脏指数，Masson染色观察心肌纤维化水平，Western blotting 方法检测心肌胶原Ⅲ、转化生长因子-β1（TGF-β1）蛋白的表达。结果 与正常对照组比较，模型组左心室射血分数（EF）和左心室短轴缩短分数（FS）明显降低（P<0.05）,心脏指数增加，心肌纤维化明显，胶原蛋白Ⅲ及TGF-β1表达水平增加（P<0.05）；与模型组比较，低剂量虾青素组和高剂量虾青素组EF和FS明显升高（P<0.05），心脏指数减低（P<0.05），心肌纤维化程度减低，心肌胶原蛋白Ⅲ、TGF-β1表达水平明显降低（P<0.05）。 结论 虾青素能够降低异丙肾上腺素诱导的心肌纤维化水平，改善心功能。     

积雪草苷对心肌梗死大鼠转化生长因子-β1、Ⅰ和Ⅲ型胶原表达的影响

目的研究积雪草苷对心肌梗死大鼠左室心肌纤维化和心肌组织转化生长因子(TGF)-β1、Ⅰ型胶原(Col)Ⅰ和Ⅲ型胶原(col)Ⅲ表达的影响。方法结扎雄性SD大鼠大鼠左冠状动脉前降支建立心肌梗死模型,随机分为假手术组、假手术+积雪草苷组、心肌梗死模型组和心肌梗死模型+积雪草苷组。造模当天给药,早晚各1次,2 w后分别测定各组大鼠心脏左心室重量与体重之比、左室梗死面积;免疫组织化学检测心肌组织非梗死区TGF-β1、ColⅠ、ColⅢ的表达。结果心肌梗死模型组和心肌梗死模型+积雪草苷组左室梗死面积无显著差异(P0.05)。心肌梗死模型+积雪草苷组的左心室重量/体重低于心肌梗死模型组(P0.05);免疫组织化学染色结果显示:与心肌梗死模型组比,心肌梗死模型+积雪草苷组非梗死区心肌TGF-β1、ColⅠ、ColⅢ的表达明显降低(P0.05)。心肌梗死大鼠非梗死区心肌梗死组织ColⅠ、ColⅢ表达与心肌组织TGF-β1的表达正相关。结论积雪草苷可减少心肌梗死大鼠非梗死区TGF-β1的表达,从而减弱非梗死区心肌组织ColⅠ、ColⅢ异常合成与沉积,减轻心肌梗死后左室心肌纤维化程度,延缓左室重构的发展。     

山茱萸环烯醚萜苷对局灶性脑缺血大鼠血管内皮生长因子及其受体表达的影响

目的研究山茱萸环烯醚萜苷（CIG）对局灶性脑缺血大鼠神经功能和血管内皮细胞生长因子（VEGF）及其受体FLK-1表达的影响。方法取成年雄性SD大鼠115只,随机分为假手术组、模型组及CIG治疗组。治疗组又分为20、60和180mg／kg剂量组,每组23只大鼠。采用大脑中动脉线栓法制作大鼠局灶性脑缺血模型,造模后3h开始灌胃给药。造模后7、14和28d,采用改良神经功能缺损评分（mNSS）评价大鼠的神经功能,用免疫组化法和Western Blot法检测VEGF蛋白表达。用RT—PCR方法检测VEGF及其受体FLK-1的mRNA表达。结果①造模后7、14和28d,与模型组相比,CIG 60和180mg／kg组大鼠mNSS均显著降低（F=2．832,F=4．970,F=2．661,均P〈0．05）;②造模后7d,模型组大鼠大脑皮质VEGF蛋白与假手术组相比无明显变化,14和28d时,VEGF蛋白表达降低;与模型组相比,7、14和28d时,CIG 60和180mg／kg组VEGF蛋白表达显著增加（F=1．202,F=1．705,F=2．189,均P〈0．05）;③造模后28d,CIG 60和180mg／kg组大鼠VEGF阳性细胞染色面积显著增加（F=13．249,均P〈0．05）;④造模后7d,与模型组相比,CIG 60和180mg／kg组大鼠大脑皮质VEGF-mRNA表达亦显著增加（F=2．389,均P〈0．05）;CIG 60和180mg／kg组FLK-1 mRNA的表达也显著增加（F=3．657,均P〈0．05）。结论CIG能明显改善局灶性脑缺血大鼠的神经功能,其机制可能与CIG促进VEGF蛋白的表达有关。     

芍药苷通过cAMP-PKA信号通路对心肌梗死大鼠保护作用的实验研究

目的探讨芍药苷对心肌梗死大鼠的保护作用,并初步探究其分子机制。方法选取50只大鼠结扎冠状动脉制作心梗模型,将造模成功大鼠分为模型组(等量生理盐水)、阳性对照组(10 mg/kg缬沙坦)、芍药苷高(100 mg/kg)、中(50 mg/kg)、低(25 mg/kg)剂量组,每组10只;另选10只作为假手术组,不结扎,其余操作同造模组,假手术组给予等量生理盐水。灌胃给药4周,观察各组大鼠心电图ST段变化、血清酶学变化、心肌组织病理情况、心肌梗死面积,并测定心肌组织中c AMP、PKA及p PKA的表达变化。结果造模组心电图中导联S-T段明显抬高,提示心肌梗死模型造模成功,可供后续实验;给药4周后,各治疗组大鼠血清中肌酸激酶(CK)、乳酸脱氢酶(LDH)活性均显著降低(P0.05),超氧化物歧化酶(SOD)活性均显著升高(P0.05),且芍药苷高剂量组血清激酶指标接近假手术组;各治疗组均能明显改善心肌细胞核固缩、碎裂、坏死等;各治疗组大鼠心肌梗死面积均显著减小(P0.05);各治疗组大鼠心肌组织中c AMP、p PKA、p CREB的表达水平均显著上调(P0.05)。结论芍药苷可能通过c AMP-PKA信号通路发挥对心肌梗死大鼠的保护作用,且治疗作用呈剂量相关性,可为临床芍药苷治疗心肌梗死提供理论参考。     

血管紧张素Ⅱ受体拮抗剂对梗死心肌肌腱蛋白分布的影响

目的探讨血管紧张素Ⅱ（AngⅡ）受体（AT1,AT2）拮抗剂对梗死心肌基质金属蛋白酶（MMPs）及细胞外基质肌腱蛋白（tenascin-c,TN-C）的调节作用。方法结扎大鼠左冠状动脉建立心肌梗死模型,术前7d起分别用安慰剂、AT1受体拮抗剂缬沙坦10mg/（kg.d）、AT2受体拮抗剂PD12331930mg/（kg.d）。术后7d放免法检测左心室游离壁（LVFW）、室间隔（IS）心肌组织基质金属蛋白酶MMP-2,3,9、基质金属蛋白酶组织抑制物-1（TIMP-1）的表达,免疫荧光检测LVFW、IS、RV心肌TN-C的分布。结果与假手术组相比,术后7d手术组、缬沙坦组及PD123319组IS和LVFW的MMP-2,3,9水平显著增加,TIMP-1水平显著减少（P<0.01）;TN-C在RV心肌组织及假手术组中不表达,在手术组和PD123319组IS和LVFW中表达增强,缬沙坦组表达较弱。结论AngⅡ参与梗死心肌组织的重构,通过AT1作用于MMPs,调节细胞外基质TN-C等,AT1受体拮抗剂的心脏保护作用与其抑制MMPs及TN-C有关。     

缬沙坦与螺内酯对肾血管性高血压大鼠

目的探讨在高血压左室肥厚形成过程中心肌局部RAAS及机械负荷等不同因素对c-myc表达的作用及机制。方法采用两肾一夹（2K1C）法建立肾血管性高血压大鼠模型,随机分为高血压组（H组）、螺内酯组(螺内酯50 mg·kg^-1·d^-1灌胃,S组)、缬沙坦组(缬沙坦30 mg·kg^-1·d^-1灌胃,V组)、螺内酯和缬沙坦联用组(螺内酯50 mg·kg^-1·d^-1+缬沙坦30 mg·kg^-1·d^-1灌胃,S+V组),并以假手术组大鼠（C组）为对照。采用心脏超声观察各组大鼠心脏结构和功能的变化;用放射免疫法检测各组大鼠心肌组织中血管紧张素Ⅱ、醛固酮的浓度;用免疫组化法检测各组大鼠心肌组织中c-myc的表达情况。结果用药8周后V组、S+V组的血压、左室收缩期径线室壁应力、舒张末期左室后壁厚度及室间隔厚度均明显低于H组及S组（P<0.05）。S组、V组、S+V组心肌组织中AngⅡ低于H组（P<0.05）。H组与S组左室心肌细胞中c-myc表达量较C组、V组及S+V组明显上升（P<0.01）。c-myc蛋白的表达量与用药8周时颈动脉收缩压、左室收缩期径线室壁应力呈正相关（r=0.848,P<0.01;r=0.580,P<0.01）,与心肌组织中AngⅡ的浓度不相关。结论机械负荷的增加是诱导肾血管性高血压大鼠左室心肌细胞中c-myc表达持续增强的重要因素,且c-myc的持续表达不依赖于心肌局部血管紧张素Ⅱ的激活。     

缬沙坦与螺内酯对肾血管性高血压大鼠

目的探讨在高血压左室肥厚形成过程中心肌局部RAAS及机械负荷等不同因素对c-myc表达的作用及机制。方法采用两肾一夹（2K1C）法建立肾血管性高血压大鼠模型,随机分为高血压组（H组）、螺内酯组(螺内酯50 mg·kg^-1·d^-1灌胃,S组)、缬沙坦组(缬沙坦30 mg·kg^-1·d^-1灌胃,V组)、螺内酯和缬沙坦联用组(螺内酯50 mg·kg^-1·d^-1+缬沙坦30 mg·kg^-1·d^-1灌胃,S+V组),并以假手术组大鼠（C组）为对照。采用心脏超声观察各组大鼠心脏结构和功能的变化;用放射免疫法检测各组大鼠心肌组织中血管紧张素Ⅱ、醛固酮的浓度;用免疫组化法检测各组大鼠心肌组织中c-myc的表达情况。结果用药8周后V组、S+V组的血压、左室收缩期径线室壁应力、舒张末期左室后壁厚度及室间隔厚度均明显低于H组及S组（P<0.05）。S组、V组、S+V组心肌组织中AngⅡ低于H组（P<0.05）。H组与S组左室心肌细胞中c-myc表达量较C组、V组及S+V组明显上升（P<0.01）。c-myc蛋白的表达量与用药8周时颈动脉收缩压、左室收缩期径线室壁应力呈正相关（r=0.848,P<0.01;r=0.580,P<0.01）,与心肌组织中AngⅡ的浓度不相关。结论机械负荷的增加是诱导肾血管性高血压大鼠左室心肌细胞中c-myc表达持续增强的重要因素,且c-myc的持续表达不依赖于心肌局部血管紧张素Ⅱ的激活。     

吡非尼酮通过调节急性心肌梗死大鼠TGF-β1/Smad通路改善心室重构

摘要 目的：探讨吡非尼酮调节急性心肌梗死大鼠TGF-β1/Smad通路对心室重构的影响。方法：将72只SD大鼠随机分为假手术组、模型组、吡非尼酮低剂量组（50mg/kg）、吡非尼酮中剂量组(100mg/kg)、吡非尼酮高剂量组(200mg/kg)、福辛普利组（阳性对照组,15mg/kg）,每组12只。除假手术组外,其余各组大鼠制备急性心肌梗死模型,药物处理组大鼠每天灌胃治疗,假手术组及模型组大鼠以同剂量生理盐水灌胃,持续14d,给药结束24h后,检测大鼠左心室质量指数;伊红（HE）、天狼星红染色分别检测大鼠心肌组织病理形态变化及心室纤维化程度;酶联免疫吸附法（ELISA）检测各组大鼠血清中肿瘤坏死因子-α（TNF-α）、白细胞介素-6（IL-6）、转化生长因子β（TGF-β1)水平;免疫印迹实验（Western blot）检测各组大鼠心肌组织TGF-β1/Smad通路蛋白的表达情况。结果：与假手术组比较,模型组大鼠心肌组织形态改变明显,呈现心肌细胞肥大、坏死,心肌纤维扭曲、断裂,炎性细胞浸润等病理损伤,并有大量胶原沉积,呈现纤维化变性,左心室质量指数增大、血清TNF-α、IL-6及TGF-β1水平、心肌组织TGF-β1表达及p-Smad/Smad明显升高（P均＜0.05）。吡非尼酮低、中、高剂量组、福辛普利组大鼠病理损伤及纤维化程度较模型组轻,左心室质量指数、血清TNF-α、IL-6及TGF-β1水平、心肌组织TGF-β1表达及p-Smad/Smad较模型组降低,且吡非尼酮各组呈剂量依赖性（P均＜0.05）;吡非尼酮高剂量组与福辛普利组比较,差异无统计学意义（P>0.05）。结论：吡非尼酮可抑制心肌梗死大鼠心肌炎症,降低病理损伤及纤维化变性,改善心室重构,可能是通过下调TGF-β1/Smad通路实现的。     

重组脑钠尿肽对慢性心力衰竭大鼠心脏功能和心肌细胞钠电流的影响

目的 研究重组人脑钠尿肽(recombinant human brain natriuretic peptide, rhBNP)对慢性心力衰竭（chronic heart failure,CHF）大鼠心脏功能及钠电流的影响。 方法 采用主动脉缩窄术（transverse aortic constriction,TAC）来构建CHF大鼠模型;将60只（6-8）周龄的SPF级SD雄性大鼠随机分为假手术（sham）组、模型组、rhBNP组、卡托普利（CAP）组; rhBNP组、CAP组从术后第4周后分别以rhBNP（25 μg/kg）（次·日）、CAP（2 mg/kg）（次·日）,灌胃给药,给药4周后,HE染色观察大鼠心组织病变;全细胞膜片钳技术测定各组心肌细胞钠离子电流;Western blot检测Nav1.5蛋白的表达。 结果 与sham组相比,模型组CHF病理症状明显,钠电流明显降低,Nav1.5的表达明显降低（P<0.05）;与模型组相比,rhBNP组、CAP组CHF病理症状明显缓解,钠电流明显升高,Nav1.5的表达明显升高（P<0.05）。 结论 rhBNP能够改善CHF大鼠的心脏功能,抑制心室重构,并且能够阻止CHF大鼠心肌细胞钠电流的降低,使Nav1.5蛋白的表达升高。     

CAR和Cx45在房室传导阻滞大鼠房室结区的表达

目的 研究急性心肌梗死后房室传导阻滞（AVB）大鼠房室结区柯萨奇病毒-腺病毒受体（CAR）和缝隙连接蛋白（Cx）45定位和表达情况，了解缺血相关AVB阻滞的发生机制及房室结区的电生理特征。 方法 选择SD大鼠，随机分为模型组(n =12) 和假手术（SH）组(n = 6)。模型组根据AVB持续时间不同分为AVB 2h组（n = 6）和AVB 4h组（n = 6）。结扎大鼠右冠状动脉建立AVB阻滞模型，分别于建模后2h和4h对模型组和SH组取材。对房室结区行连续切片，行免疫荧光标记检测CAR和Cx45的定位及表达情况。行Western blot定量分析各组房室结区CAR和Cx45蛋白的表达情况。 结果 免疫荧光标记显示CAR和 Cx45主要定位于房室结，模型组（AVB 2 h和AVB 4 h组）与SH组相比，CAR和Cx45表达增加。Western blot显示AVB 2 h组CAR和 Cx45 表达增加，与SH组相比，蛋白表达差异有统计学意义（P< 0.05）; AVB 4 h组相比于SH组蛋白表达增多，但无统计学意义；CAR和Cx45蛋白表达相关性分析显示，CAR和 Cx45的表达具有明显正相关(r = 0.703，P< 0.05)。 结论 急性心肌梗死后AVB阻滞早期大鼠房室结区CAR和Cx45表达增加，且CAR和Cx45的表达呈正相关。     

辛伐他汀对非缺血性心力衰竭大鼠血红素氧合酶-1表达和心室重构的影响

目的 观察辛伐他汀对盐酸多柔比星(商品名:阿霉素)制备的非缺血性心力衰竭模型大鼠血红素氧合酶-1(HO-1)表达与心窒重构的影响. 方法 Wistar大鼠正常组18只.阿霉素腹腔注射2.5 mg·kg-1·d-1,每周3次,累积剂量15 mg/kg,分为模型组20只,他汀干预组19只(2周后给予辛伐他汀20 mg·kg-1·d-1灌胃,共4周).另选9只大鼠,于上述大鼠干预3周购进,经1周适应环境后,给予上述方法阿霉素腹腔注射,为2周组.分别进行血流动力学检查,测定心肌HO-1的mRNA表达、羟脯氨酸含量与病理分析. 结果 6周时模型组与他汀干预组的左心室收缩最人速率(+LVdp/dtmax)与舒张的最大速率(-LVdp/dtmax)均明显下降,其中+LVdp/dtmax两组分别下降28.2%与11.9%,-LVdp/dtmax两组分别下降33.0%与27.9%(F分别为4.899、3.80均为P<0.01);他汀干预组的±LVdp/dtmax较模型组分别高22.6%和7.5%,差异有统计学意义(F=2.461,P<0.05).2周时大鼠心肌羟脯氨酸含量即开始升高,分别为[(485.0±52.9)g/kg和(364.0±41.6)g/kg,F=0.441,P<0.01];6周时,模型组心肌羟脯氨酸含量继续升高为(572.9±75.4)g/kg,F=0.654,P<0.05;而他汀下预组心肌羟脯氨酸含量与2周组[(475.9±86.5)g/kg]比较,差异无统计学意义.6周时模型组大鼠心肌HO-1表达较正常组增高,分别为0.6217±0.1229与0.2475±0.1053,F=0.128,P<0.01;辛伐他汀干预使HO-1的表达进一步升高,分别为0.7860±0.1133和0.6217±0.1229,F=3.622,P<0.05. 结论心力衰竭大鼠心肌HO-1表达增高,辛伐他汀可进一步卜调衰竭心肌HO-1的表达,从而减轻心肌损伤与心力衰竭的程度.     

Acidic and basic fibroblast growth factors involved in cardiac angiogenesis following infarction

Acidic and basic fibroblast growth factors (FGF-1/FGF-2) promote angiogenesis in cancer. Angiogenesis is integral to cardiac repair following myocardial infarction (MI). The potential regulation of FGF-1/FGF-2 in cardiac angiogenesis postMI remains unexplored. Herein, we examined the temporal and spatial expression of FGF-1/FGF-2 and FGF receptors (FGFR) in the infarcted rat heart at days 1, 3, 7, and 14 postMI. FGF-1/-2 gene and protein expression, cells expressing FGF-1/-2 and FGFR expression were examined by quantitative in situ hybridization, RT-PCR; western blot, immunohistochemistry and quantitative in vitro autoradiography. Compared to the normal heart, we found that in the border zone and infarcted myocardium 1) FGF-1 gene expression was increased in the first week postMI and returned to control levels at week 2; FGF-1 protein levels were, however, largely reduced at day 1, then elevated at day 3 peaked at day 7 and declined at day 14; and cells expressing FGF-1 were primarily inflammatory cells; 2) FGF-2 gene expression was significantly elevated from day 1 to day 14; the increase in FGF-2 protein level was most evident at day 7 and cells expressing FGF-2 were primarily endothelial cells; 3) FGFR expression started to increase at day 3 and remained elevated thereafter; and 4) FGF-1/FGF-2 and FGFR expression remained unchanged in the noninfarcted myocardium. Thus, FGF-1/FGF-2 and FGFR expression are enhanced in the infarcted myocardium in the early stage after MI, which is spatially and temporally coincident with angiogenesis, suggesting that FGF-1/FGF-2 are involved in regulating cardiac angiogenesis and repair.     

An oral formulation of angiotensin-(1-7) produces cardioprotective effects in infarcted and isoproterenol-treated rats

In this study we evaluated the cardiac effects of a pharmaceutical formulation developed by including angiotensin (Ang)-(1-7) in hydroxypropyl β-cyclodextrin (HPβCD), in normal, infarcted, and isoproterenol-treated rats. Myocardial infarction was produced by left coronary artery occlusion. Isoproterenol (2 mg/kg, IP) was administered daily for 7 days. Oral administration of HPβCD/Ang-(1-7) started immediately before infarction or associated with the first dose of isoproterenol. After 7 days of treatment, the rats were euthanized, and the Langendorff technique was used to analyze cardiac function. In addition, heart function was chronically (15, 30, 50 days) analyzed by echocardiography. Cardiac sections were stained with hematoxylin/eosin and Masson trichrome to evaluate cardiac hypertrophy and damage, respectively. Pharmacokinetic studies showed that oral HPβCD/Ang-(1-7) administration significantly increased Ang-(1-7) on plasma whereas with the free peptide it was without effect. Oral administration of HPβCD/Ang-(1-7) (30 μg/kg) significantly reduced the deleterious effects induced by myocardial infarction on systolic and diastolic tension, ±dT/dt, perfusion pressure, and heart rate. Strikingly, a 50% reduction of the infarcted area was observed in HPβCD/Ang-(1-7)-treated rats. Furthermore, HPβCD/Ang-(1-7) attenuated the heart function impairment and cardiac remodeling induced by isoproterenol. In infarcted rats chronically treated with HPβCD/Ang-(1-7), the reduction of ejection fraction and fractional shorting and the increase in systolic and diastolic left ventricular volumes observed in infarcted rats were attenuated. Altogether, these findings further confirm the cardioprotective effects of Ang-(1-7). More importantly, our data indicate that the HPβCD/Ang-(1-7) is a feasible formulation for oral administration of Ang-(1-7), which can be used as a cardioprotective drug.     

不同剂量利多卡因对腹腔镜子宫肌瘤切除术患者麻醉诱导时QTc的影响

目的 分析不同剂量利多卡因对腹腔镜子宫肌瘤切除术患者麻醉诱导期间按心率校正的QT间期(QTc)的影响.方法 纳入2019年6月～ 2019年12月在山西医科大学第一医院行腹腔镜子宫肌瘤切除术的患者共80例,采用随机数字表法分配到4组(等容积但不同剂量利多卡因或生理盐水),分别为:A组(空白剂量组,生理盐水)、B组(低剂...     

褪黑素抗糖尿病所致心肌损伤的作用研究

目的 探讨褪黑素（melatonin，MLT）在链脲佐菌素（streptozotocin，STZ）诱导的糖尿病（DM）大鼠心肌损伤中发挥的作用。 方法 将30只成年雄性SD大鼠随机分为对照组、DM模型组和MLT治疗组。大鼠连续5 d腹腔注射STZ（50 mg/kg）诱导糖尿病大鼠模型，造模成功后腹腔注射MLT（30 mg/kg）治疗8周。8周后，尾静脉取血检测大鼠空腹血糖和血清胰岛素水平；心脏超声检测各组大鼠心脏功能；HE和Masson染色检测心肌组织形态变化；原位末端标记法（TUNEL）检测心肌细胞凋亡；ELISA试剂盒检测血清和心肌组织氧化应激相关体液因子水平和炎症因子水平。 结果 与对照组相比，糖尿病大鼠血糖升高、血清胰岛素水平降低，心脏超声结果显示糖尿病大鼠心脏收缩舒张功能降低，HE和Masson染色显示糖尿病大鼠心肌细胞形态紊乱、胶原聚集，TUNEL法检测结果显示糖尿病大鼠心肌细胞凋亡增加，ELISA法检测结果显示糖尿病大鼠血清MDA水平明显增加、SOD、CAT水平明显减少，炎症因子TNF-α和IL-1β水平明显增加；与DM模型组相比，MLT治疗组大鼠血糖水平明显降低、血清胰岛素水平明显增加，治疗组大鼠心脏收缩和舒张功能、心肌形态的紊乱和胶原的产生均有所改善；心肌细胞凋亡明显减少，血清的MDA水平减少、SOD、CAT的水平增加，TNF-α和IL-1β的水平也有明显减少。 结论 MLT具有减轻糖尿病所致心肌损伤的作用，其作用机制是否与其发挥抗氧化活性尚需进一步研究证实。     

Delineation of acute myocardial infarction with dysprosium DTPA-BMA: influence of dose of magnetic susceptibility contrast medium.

OBJECTIVES. The contrast enhancement of acutely infarcted myocardium produced by the nonionic magnetic susceptibility-enhancing agent dysprosium diethylenetriamine pentaacetic acid-bis-methylamide (DyDTPA-BMA [S-043 Injection]) was assessed in the current study to establish the lowest dose that would yield optimal contrast between normal and acutely infarcted myocardium. BACKGROUND. Magnetic susceptibility contrast agents enhance differences between normal and ischemic tissue by reducing the signal of the normally perfused tissue to which they distribute. METHODS. Acute myocardial infarctions were produced by ligation of the left coronary artery. At 3 to 4 h after occlusion, a dose of 0.1, 0.3 or 0.5 mmol/kg of DyDTPA-BMA was injected intravenously into eight rats each in group 1, 2 or 3, respectively; a fourth group of seven rats served as a control group. Nuclear magnetic resonance (NMR) transverse relaxation time (T2)-weighted images (electrocardiographically gated to every 5th beat, echo delay time [TE] = 60 ms) were acquired before and for 1 h after administration of contrast agent. RESULTS. Images obtained before the injection of contrast agent showed moderate differences in signal intensity between normal and infarcted myocardium (p < 0.05). The contrast enhancement and the duration of delineation between infarcted and normal myocardium produced by this agent were dose dependent. At doses of 0.1, 0.3 and 0.5 mmol/kg, DyDTPA-BMA produced signal loss in normal myocardium: 63 +/- 5%, 41 +/- 4% and 28 +/- 4% of the baseline values, respectively, without any significant reduction in signal intensity of the infarcted region. The reduction in signal of normal myocardium and delineation of the infarct persisted for 5 min at a dose of 0.1 mmol/kg, for 20 min at a dose of 0.3 mmol/kg and for 40 min at a dose of 0.5 mmol/kg. No change in signal intensity or signal intensity ratio between normal and infarcted myocardium was observed in the control group during the same observation period. CONCLUSIONS. These results suggest that low doses of this agent, comparable to those of longitudinal relaxation time (T1)-enhancing agents, can delineate acutely infarcted myocardium. A dose of 0.3 mmol/kg of DyDTPA-BMA (S-043 Injection) provides reasonably persistent demarcation of acute myocardial infarction. Because this dose dramatically suppresses the NMR signal of normal myocardium, it shows the infarcted region as a region of high intensity (bright spot) on NMR images.     

Coronary reserve is depressed in postmyocardial infarction reactive cardiac hypertrophy

After a myocardial infarction (MI), the remaining myocardium undergoes a compensatory reactive hypertrophy. Although coronary perfusion to the surviving myocardium can be an important determinant of cardiac function in this setting, there are no available data regarding myocardial blood flow in reactive hypertrophy. Accordingly, we measured coronary blood flow and reserve using radioactive microspheres in rats 4 weeks after induction of an MI by ligation of the left coronary artery. Maximal coronary dilation was induced by Carbochrome, a potent coronary vasodilator, infused at a rate of 0.45 mg/kg/min up to a total dose of 12 mg/kg. Sham-operated rats served as controls. All animals in the infarct group had a large MI affecting 30-51% (average, 41%) of the left ventricle. Left ventricular end-diastolic pressure was significantly elevated (30 +/- 6.5 vs. 8.0 +/- 2.5 mm Hg in sham-operated rats, p less than 0.01) and baseline hemodynamic indexes of cardiac performance were significantly (p less than 0.01) reduced in this group. Myocyte cross-sectional area measurements were used as an index to quantify the degree of reactive hypertrophy and indicated that the infarcted animals had, on average, a 30% hypertrophic response of the surviving left ventricular myocardium. In the infarcted animals, both coronary flow and vasodilator reserve in the surviving myocardium were depressed. Maximal coronary blood flow in the remaining myocardium was significantly lower than that measured in the sham-operated animals (839 and 1,479 ml/min/100 g, respectively; p less than 0.001). Similarly, minimal coronary resistance was significantly higher in the MI group as compared with the sham group (0.12 vs. 0.07 mm Hg/ml/min/100 g, respectively; p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)     

钙通道阻滞剂对梗死心肌中不同部位心肌连接蛋白43表达的影响

目的:研究L和L/T型钙通道阻制剂对梗死心脏不同部位(坏死区域、肥厚区域等)心肌组织中连接蛋白43（Cx43）的影响。方法: 随机将大鼠48只分为假手术组、心肌梗死(MI)组、阿莫地平(L型钙通道阻滞剂)组和米贝拉地尔(L/T型钙通道阻滞剂)组(每组n=12只)。通过结扎大鼠左冠状动脉建立MI模型,术前7 d,上述4个组分别用安慰剂、L型钙通道阻滞剂阿莫地平4 mg/(kg·d)和L/T型钙通道阻滞剂米贝拉地尔10 mg/(kg·d)。术后1、3、7 d,分别检测左心室游离壁（LVFW,梗死区）、心室间隔（IS,肥厚区）和右心室壁（RV）,正常心肌组织中Cx43蛋白的表达。术后7 d显微直视下测LVFW处MI病灶的大小、IS的厚度及左心室的大小。结果: IS中Cx43蛋白表达于术后1、3、7 d呈逐渐增加的趋势;LVFW中Cx43蛋白的表达于术后1、3、7 d时均处于低水平,与对照组相比差异显著（P<0.05）。RV中Cx43蛋白的表达于术后1、3、7 d无显著差异,与对照组相比也无显著性差异。米贝拉地尔能明显地抑制LVFW心肌组织中Cx43表达的下调,缩小MI病灶;阿莫地平则抑制肥厚心肌中Cx43蛋白的表达,明显抑制IS的肥厚。结论: MI病理过程中,梗死病灶内Cx43的表达下调,肥厚组织中Cx43的表达上调。L和L/T型钙通道阻滞剂均能减轻心肌重构与选择性地调节心肌组织中Cx43的表达有关。