镍钛合金丝对大鼠心肌细胞肌浆网钙泵及雷尼丁受体的影响

背景：虽然镍钛合金封堵器置入治疗先天性心脏病具有较好的临床效果,但后期发生心律失常并发症的概率较大。目的：观察镍钛合金对大鼠心肌细胞肌浆网钙泵及雷尼丁受体表达的影响。方法：取30只SD大鼠,随机均分为2组,实验组于心尖部植入镍钛合金丝,对照组不做任何处理特殊处理,术后1,3,6个月取材,采用RT-PCR检测心肌细胞肌浆网钙泵与雷尼丁受体基因的表达,采用免疫组化检测心肌细胞肌浆网钙泵及雷尼丁受体蛋白的表达,采用苏木精-伊红染色检测炎症反应情况。结果与结论：实验组镍钛合金植入大鼠心肌后,炎症细胞浸润,引发炎症反应,伴纤维组织增生,随着植入时间延长,炎症反应逐渐消失;对照组未见炎细胞浸润。两组术后不同时间点的心肌细胞肌浆网钙泵、雷尼丁受体基因表达比较差异无显著性意义,相应的蛋白表达比较差异也无显著性意义。表明镍钛合金丝不影响心肌细胞肌浆网钙泵、雷尼丁受体的表达,提示镍钛合金封堵器相关心律失常可能与肌浆网钙泵、雷尼丁受体蛋白表达异常机制关系不大。 中国组织工程研究杂志出版内容重点：生物材料;骨生物材料; 口腔生物材料; 纳米材料; 缓释材料; 材料相容性;组织工程     

神经肽Y诱导大鼠心肌细胞内游离钙重分布研究

目的: 观察神经肽Y(NPY)对大鼠心肌细胞胞浆钙浓度和肌浆网(SR)内钙含量的影响。方法: 用100 nmol·L^-1 NPY刺激Sprague-Dawley乳鼠心肌细胞24 h, 用荧光染料Fluo-4 AM负载胞浆钙, 记录静息状态下心肌细胞胞浆钙浓度，并用咖啡因诱导的胞浆钙瞬变幅度来反映肌浆网内总钙负荷；用荧光染料Fluo-5N AM 直接标记心肌细胞肌浆网内游离钙离子。所有钙影像均由Leica SP2激光共聚焦显微镜记录。结果: 100 nmol·L^-1 NPY刺激24 h后，心肌细胞胞浆游离钙浓度明显高于对照组（P<0.05）；心肌细胞肌浆网内游离钙含量明显低于对照组 (P<0.01)；咖啡因诱导下钙瞬变幅度也低于对照组。结论: 24 h NPY刺激可导致心肌细胞内游离钙出现空间分布的变化，即胞浆钙浓度增高而肌浆网内钙负荷减少。     

雄性大鼠心肌雄激素受体及其mRNA的表达

目的观察雄激素受体(AR)蛋白及其mRNA在大鼠心肌的表达。方法采用免疫组织化学方法和原位杂交的方法观察成年(3月龄)Wistar大鼠心肌中AR阳性神经元的存在及其表达。结果大鼠心肌中存在AR阳性神经元和ARmRNA阳性神经元。结论为AR在心脏的存在提供形态学依据,并在基因水平证实部分心肌细胞中存在雄激素受体的结合位点,提示心肌细胞可能受雄激素影响。     

大鼠心肌及动脉壁雄激素受体的探讨

采用免疫组化ＡＢＣ对３０例大鼠的心脏及动脉进行了雄激素受体的检测。结果表明在大鼠心肌和动脉壁存在着雄性激素受体，提示雄激素可能对心血管系统起调节作用。     

甘氨酸受体在大鼠心肌细胞的表达

目的：检测成年大鼠心肌组织和新生大鼠心 肌细胞是否有甘氨酸受体（GlyR）mRNA和蛋白的表达。方法：选用成年 雄性SD大鼠心肌组织和新生SD大鼠培养心肌细胞，提取总RNA和膜蛋白，用逆转录－巢式聚 合酶链反应（RT-PCR）和蛋白免疫印迹（Western blotting）检测GlyRα1和β亚基的mRNA 和蛋白表达。结果：成年大鼠心肌组织和新生大鼠培养心肌细胞均有与 脊髓组织GlyRβ亚基极为相似的mRNA和蛋白的表达；对于GlyRα1亚基，仅在新生SD大鼠培 养心肌细胞发现有mRNA的表达。结论：本研究证实在成年大鼠心肌组织 和新生大鼠心肌细胞中有与脊髓组织相似的GlyR亚基的表达，提示大鼠心肌细胞的膜上有Gl yR的存在。     

缺氧预处理对自发性高血压大鼠心肌细胞内钙的影响

目的:探讨缺氧预处理对后继缺氧再给氧所致心肌细胞内钙超载的影响及蛋白激酶C(PKC)和百日咳毒素(PTX)敏感的G-蛋白在缺氧预处理的作用.方法:循环灌流法分离自发性高血压大鼠(SHR)肥大心肌细胞,用Fu ra-2AM测定钙浓度.结果:[Ca2+].为1.0 mmol/L时,预处理组缺氧再给氧后其心肌细胞内游离钙浓度[Ca2+]i为(194.0±24.8) nmol/L,未预处理组为(297.5 ±24.5) nmol/L;无外钙预处理组缺氧再给氧后其心肌细胞[Ca2+]i为(162.0 ±30.7) nmol/L,未预处理组为(236.5±28.3) nmol/L,提示缺氧预处理可减少缺氧再给氧所致心肌细胞内钙释放及外钙内流.在[Ca2+].为1.0 mmol/L组,于预处理前分别预先给予PKC拮抗剂Staurosporine(10 nmol/L)及Gi-蛋白失活剂百日咳毒素(PTX,200 ng /L),可见经后继缺氧再给氧后其心肌细胞[Ca2+]i分别为(264.8±19.3)及(25 8.0±27.7) nmol/L,高于缺氧预处理组但低于未预处理组.结论:SH R肥大心肌细胞,缺氧预处理可减轻后继缺氧再给氧所致心肌细胞内钙超载;PKC及PTX敏感的G- 蛋白可能部分参与缺氧预处理的保护作用.     

β受体阻滞剂在慢性心衰的中的应用

在慢性心衰的发生发展中,神经内分泌激素即交感神经肾上腺素系统和肾素――血管紧张素-醛固酮系统的-紊乱起了关键作用.它们的激活程度与长期预后变化呈正相关. 慢性心衰的治疗因此产生了最新的治疗模式: 神经内分泌调控模式.近十几年来,研究人员通过药理及大型临发现,β受体阻滞剂可以有效拮抗交感神经肾上腺素系统和肾素―血管紧张素-醛固酮系统及过度激活的神经体液因子,降低血压,减慢心率.降低心肌耗氧量,加之其独有的抗心律失常的作用而成为强有力的心脏保护剂,成为心力衰竭治疗中的又一关注点.     

多巴胺受体蛋白在大鼠心肌肥厚时的表达变化

目的:观察多巴胺受体（DR）1和2 mRNA和蛋白质在大鼠病理性心肌肥厚时的表达情况。 方法:应用肾动脉缩窄术复制Wistar大鼠心肌肥厚的动物模型。于术后35 d取心脏,测定心肌肥大指数，左室内压，V-G染色观察胶原含量。应用心肌原位杂交和RT-PCR，免疫荧光，Western blotting结合图像分析系统分别检测心肌组织中多巴胺受体D1、D2 mRNA 和蛋白质的表达变化。 结果:DR1、DR2 mRNA在正常大鼠心肌组织有表达，其中血管平滑肌细胞内DR2的分布多于心室肌和心房肌细胞。模型组左心肥大明显，表现为室内压显著升高，胶原含量增多;模型组心室肌DR1和 DR2 mRNA和蛋白质的含量均明显低于假手术组。 结论:正常大鼠心肌组织存在DR1和 DR2 mRNA和蛋白质的表达，心肌肥厚时其表达明显减低，两者的关系及可能机制有待于进一步研究。     

c-kit与miR-21在心衰大鼠心肌中表达下降

目的研究c-kit与miR-21基因在大鼠左室重构中的动态表达及其作用机制。方法将大鼠140只随机分为正常对照组15只和心衰模型组125只。心衰模型制作:4 mg/kg腹腔注射阿霉素。在8周时对大鼠进行心功能检测,验证心衰模型。取心脏组织冰冻切片。利用免疫组化及免疫荧光显色等技术检测心肌组织中miR-21和c-kit的基因表达。结果 1)心衰组的呈现心肌梗死后心肌细胞的病理学变化。2)在正常和心衰心肌中miR-21阳性细胞主要表达于血管内皮,少量心肌细胞和干细胞,而心衰心肌组织中的表达量明显减少;c-kit阳性细胞常成群分布,主要聚集于心外膜及其附近。在两组心肌组织中均有少数细胞存在miR-21和c-kit共表达。结论 c-kit和miR-21在心衰大鼠心肌中表达下降与心力衰竭和左室重构呈高度相关。     

比索洛尔提高心力衰竭大鼠心肌SERCA2a活性

目的观察比索洛尔对心力衰竭大鼠心肌肌浆网钙ATP酶2a(SERCA2a)活性的影响。方法腹腔注射阿霉素建立大鼠心力衰竭模型。实验分为对照组、假手术组、模型组、比索洛尔组、卡托普利组和比索洛尔+卡托普利组。检测心功能指标;ELISA法检测血浆脑钠肽水平;茎环状引物实时定量PCR检测心肌miR-25-3p表达水平;Western blot检测心肌SERCA2a和受磷蛋白(PLB)表达水平;定磷法测定心肌SERCA2a活性。结果与对照组比较,模型组大鼠心功能明显减退(P0.01),血浆脑钠肽水平和心肌miR-25-3p表达水平明显升高(P0.01),SERCA2a和PLB表达水平、SERCA2a/PLB比值和SERCA2a活性明显降低(P0.01);与模型组比较,比索洛尔组、卡托普利组和比索洛尔+卡托普利组大鼠心功能明显改善(P0.01),血浆脑钠肽水平和心肌miR-25-3p表达水平明显降低(P0.01),SERCA2a和PLB表达水平明显升高(P0.01);比索洛尔组和比索洛尔+卡托普利组SERCA2a/PLB比值和SERCA2a活性明显高于模型组(P0.05)。结论比索洛尔可以下调心肌miR-25-3p表达水平,提高SERCA2a和PLB表达水平,增强SERCA2a活性。     

Sarcoplasmic reticulum of human skeletal muscle: age-related changes and effect of trainirig

The effect of ageing on human skeletal muscle was investigated using needle biopsies from young and aged subjects and from aged subjects trained with different activity patterns. Histochemical staining for myofibrillar ATPase of ageing m. vastus lateralis demonstrated an unchanged fibre type distribution but a selective atrophy of type IIa and type IIb fibres. Analysis of myosin heavy chain (MHC) composition showed that type I MHC increased with ageing (P< 0.05). The relative content of the MHC isoforms correlated with the relative area of the respective fibre types. Sarcoplasmic reticulum (SR) proteins were investigated in muscle extracts by electrophoretic and immunoblotting techniques. When compared to a young control group (28 0.1 years old, n = 7) blots of post-myofibrillar supernatant proteins probed with polyclonal antibodies to the rabbit fast SR Ca-ATPase, a marker of extrajunctional SR, showed that the content of Ca-ATPase was significantly lower (P < 0.05) in the old control group (68 ± 0.5 years old, n= 8). On the other hand the content of calsequestrin (CS), the major intraluminal protein of SR terminal cisternae (TC), and of the 350-kDa ryanodine-binding protein, which is localized in the junctional regions of TC, did not show a concomitant decrease. These results suggest that ageing differentially affects extrajunctional and junctional SR of human skeletal muscle. These age-related changes were not observed within a group of old strength-trained subjects.     

凋亡相关蛋白在曲美他嗪干预的心力衰竭大鼠心肌细胞中的表达

目的:探讨曲美他嗪对心力衰竭心肌细胞凋亡情况及Bax、Bcl-2蛋白表达的影响.方法:随机将雄性Wistar大鼠分为假手术组、心衰组和曲美他嗪组,除假手术组其他组大鼠均采用腹主动脉缩窄术建立心衰模型.观察各组大鼠的血流动力学参数,H-E染色观察大鼠心肌细胞病理形态结构,透射电镜观察心肌细胞超微结构,原位缺口末端标记(TUNEL)法检测心肌细胞凋亡指数(AI);免疫组织化学检测各组大鼠心肌细胞Bax、Bcl-2蛋白的表达情况.结果:与模型组比较,曲美他嗪组大鼠心功能明显改善,AI明显降低,Bcl-2阳性表达显著增高,Bax阳性表达明显降低.结论:曲美他嗪可促进抑凋亡蛋白Bcl-2的表达,抑制促凋亡蛋白Bax的表达,该机制可能参与了曲美他嗪的心保护作用.     

黄连素抑制慢性心衰大鼠心肌炎性反应

 目的 在慢性心衰(CHF)大鼠模型检测Toll样受体4(TLR4)的表达,探讨黄连素在慢性心衰炎性反应干预中可能的作用机制。方法 大鼠每周腹腔注射阿霉素2.8mg/kg共10周建立慢性心衰模型,将其随机分为黄连素组、安慰剂组及对照组,每组10只。黄连素组给予黄连素每天21mg/kg灌胃4周,另两组给予等量生理盐水。用酶联吸附免疫反应法(ELISA)检测大鼠血清中BNP、TNFα、IL-1及IL-6的含量;qRT-PCR法检测大鼠血清诱生型一氧化氮合酶(iNOS)表达;HE染色观察大鼠心肌细胞形态学改变;免疫组织化学观察大鼠心肌TLR4蛋白表达和分布。结果 黄连素组大鼠血清TNFα、IL-1、IL-6及iNOS mRNA水平显著低于安慰剂组(P<0.05);黄连素组及安慰剂组TLR4吸光度值均高于对照组,而黄连素组显著低于安慰剂组(P<0.05)。结论 黄连素可能通过抑制TLR4 信号传导抑制慢性心衰炎性反应。     

心肌细胞钙稳态失调在心力衰竭中作用的研究进展

心肌细胞的钙稳态依赖于质膜、肌/内质网(SR)、线粒体等对钙(Ca2+)转运的调节.胞质钙超载、SR钙渗漏等在内的钙稳态失调,使心肌细胞钙瞬变减低,收缩力下降是心力衰竭的主要特征之一.     

Stress-induced modification of the sarcoplasmic reticulum Ca transport system of the heart and its resistance to endogenous damaging factors

Research Institute of General Pathology and Pathological Physiology, Academy of Medical Sciences of the USSR, Moscow. (Presented by Academician of the Academy or Medical Sciences of the USSR G. N. Kryzhanovskii.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 108, No. 9, pp. 271–274, September, 1989.     

Calcium uptake and release through sarcoplasmic reticulum in the inferior oblique muscles of patients with inferior oblique overaction

We characterized and compared the characteristics of Ca2+ movements through the sarcoplasmic reticulum of inferior oblique muscles in the various conditions including primary inferior oblique overaction (IOOA), secondary IOOA, and controls, so as to further understand the pathogenesis of primary IOOA. Of 15 specimens obtained through inferior oblique myectomy, six were from primary IOOA, 6 from secondary IOOA, and the remaining 3 were controls from enucleated eyes. Ryanodine binding assays were performed, and Ca2+ uptake rates, calsequestrins and SERCA levels were determined. Ryanodine bindings and sarcoplasmic reticulum Ca2+ uptake rates were significantly decreased in primary IOOA (p < 0.05). Western blot analysis conducted to quantify calsequestrins and SERCA, found no significant difference between primary IOOA, secondary IOOA, and the controls. Increased intracellular Ca2+ concentration due to reduced sarcoplasmic reticulum Ca2+ uptake may play a role in primary IOOA.     

Succinate dehydrogenase activity of isolated myocardial mitochondria in chronic heart failure

Succinate dehydrogenase (SD) activity of mitochondria isolated from the muscle cells of the chronically failing heart was studied. Highest SD activity was found in mitochondria of condensed type. Low enzyme activity was observed in orthodox mitochondria. SD activity in mitochondria of intermediate type was midway between activity of the enzyme in orthodox and condensed mitochondria. Orthodox and intermediate forms of mitochondria were predominant in the fraction tested, reflecting lowered SD activity in the heart muscle tissue. Biochemical investigation of the mitochondrial fraction revealed a state of mild uncoupling of respiration and oxidative phosphorylation. The observed decrease in SD activity evidently characterizes a state of overstrain of the energy-producing structures.Department of Pathological Anatomy, Faculty of Stomatology, Moscow Medical Stomatological Institute. Central Research Laboratory, Central Postgraduate Medical Institute, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR A. I. Strukov.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 81, No. 1, pp. 37–40, January, 1976.     

Effects of fatigue on depolarization‐ and caffeine‐induced contractures of skinned fibres

Aims: Fatigue has been shown to cause intrinsic alterations in sarcoplasmic reticulum (SR) Ca²⁺ release. Methods: In this investigation, frog semitendinosus muscles were stimulated to fatigue, in vitro (80 Hz, 100 ms, 1 train s^?1, 5 min). Immediately after stimulation, single fibres were removed and skinned using either chemically or mechanically skinning. Contralateral muscle were treated similarly but were not stimulated. Results: In fatigued, saponin skinned fibres, contracture responses to low [caffeine] (4–8 mm ) were depressed compared with control. However, responses to high concentrations (10–15 mm ) were not different between conditions. In the fatigued, mechanically skinned fibres, responses to chloride depolarization were depressed at all [chloride] (20–100 mm ) compared with control. Conclusions: These results suggest that fatigue causes intrinsic alterations in both the SR Ca²⁺ release channel as well as communication between the transverse‐tubule and the SR.