家兔房室交界区及其心房传导通路的形态学研究

目的：探讨射频消融改良房室交界区的形态学基础。方法：健康成年家兔10只，分别做房室交界区的额状面、矢状面及水平面连续切片，在HE、Masson及磷钨酸苏木素染色下观察其形态学特征。结果：家兔房室结位于房室隔内中心纤维体的右侧，主要由P细胞和T细胞组成，以P细胞为主，其向后形成的延伸部同射频消融慢径的部位吻合，且细胞分布明显较房室结稀疏，内有胶原纤维分隔。同时有四条过渡细胞带分别从心房的不同部位到达房室结及后延伸部，分别称为左房结束、右房结束、后房结束及上房结束。另外，在冠状窦前壁有P细胞成团分布。结论：①房室交界区的概念应当扩大，分布范围从房室隔内中心纤维体的右侧一直向后接近冠状窦口，前部可能为快传导区，后部可能为慢传导区。②房内传导通路确有存在，并且可能参与了房内折返性心律失常的形成。③冠状窦是一个重要的结外潜在起搏点，可能与某些房性自律性心律失常的发生有关。     

成人心脏传导系统中连接蛋白43的表达

目的 探讨成人心脏及传导系统窦房结,房室结,浦肯野纤维中连接蛋白43(CX43)的表达情况。方法 免疫组织化学SABC法。结果 CX43在窦房结及房室结周围细胞膜呈散在、少量表达,在浦肯野细胞膜可见线性、细长阳性颗粒,在心房及心室肌阳性颗粒主要位于端端相连部位的闰盘处。结论 CX43在传导系统的表达与心脏传导系统的电生理传导特性相符。     

成人与新生儿心脏连接蛋白43表达差异

目的　探讨成人与新生儿心脏连接蛋白 4 3(Cx4 3)表达差异。　方法　应用SP免疫组织化学和图像分析方法 ,观测成人与新生儿心脏Cx4 3的蛋白表达。　结果　 1 新生儿心脏Cx4 3在心房和心室均呈斑点状遍布于心肌细胞侧面连接处和细胞质内 ,闰盘处极少。 2 成人Cx4 3表达在心房肌非均质分布于细胞侧面连接处和端闰盘处 ;心室肌典型地排列在闰盘处。 3 图像分析表明 ,心肌细胞Cx4 3分布密度 ,新生儿心房 <心室 ,成人心房 >心室。成人心房、心室均低于新生儿。　结论　新生儿Cx4 3主要分布于心肌细胞侧连接处 ,成人心房和心室存在差异。Cx4 3分布密度新生儿心房 <心室 ,成人心房 >心室 ;成人心脏低于新生儿。提示 ,Cx4 3有增龄变化。     

家猪房室交界区的组织学观察

利用石蜡切片 ,HE和 Masson染色 ,光镜观测了 7例猪房室交界区的形态学和组织学特征。家猪房室结位于冠状窦口前方 ,大小为 7.0 2× 2 .6 5× 1.2 9mm3。传导细胞分两类 :1细胞短柱状 ,有时有分叉 ,细胞质内有横纹 ,核相对较大 ,此类细胞多位于结上部和前部 ;2典型的移行细胞 ,多位于结的后部和下部。有 2例存在副房室结。结上部和前部、房室束、右束支内的细胞在形态上介于 Purkinje细胞和心肌之间 ,未见典型的 P细胞。说明猪的传导细胞与其它哺乳动物有差异 ,但不同形式的传导细胞却在履行相同的传导功能     

大鼠肝纤维化Ito细胞纤维连接蛋白受体α5β1的表达

研究纤维连接蛋白受体α５β１在大鼠肝纤维化中的作用。     

家猫房室结的形态学特征

哺乳动物房室结及房室交界区的毗邻结构特点国内外学者己有较多的报道[1-2],表明不同动物的房室结存在物种差异.猫作为常用的心脏实验动物[3],其房室结的结构特点未见系统的文献报道.本研究拟用光镜观察猫房室结的形态结构,为猫心传导系的基础研究提供生物学资料.     

经食管心房调搏对房室交界区前向连续传导的观察

目的 初步探讨随起搏频率增加时房室交界区前向连续传导的心电图表现特点．方法 对100例经食管心房分级递增起搏中房室交界区前向连续传导的特征分析．结果 房室交界区前向连续传导呈1：1-文氏-2：1以上传导特点变化，极少由1：1直接转为2：1传导．结论 随着起搏频率的增加，房室交界区前向连续传导呈递减性，符合慢反应电位传导特征。     

成人下颌下腺内瘦素和瘦素受体的表达及意义

目的 观察成人下颌下腺内瘦素和瘦素受体的表达和分布。方法 HE染色法和免疫组织化学SABC法。结果 成人下颌下腺内闰管、纹状管和部分小叶间导管上皮细胞呈瘦素及瘦素受体免疫阳性反应，免疫反应产物分布于导管上皮细胞胞质内，细胞核呈阴性反应。结论 成人下颌下腺内有瘦素和瘦素受体表达，可能参与调节胃肠功能及下颌下腺自身的分泌活动。     

连接蛋白43在小鼠胚胎心的时空表达规律

目的:探讨连接蛋白43 (Cx43)在小鼠胚胎心的时空表达规律及意义.方法:用抗Cx43、抗心肌肌球蛋白重链(MHC)和抗横纹肌肌节肌动蛋白(α-SCA)对胚龄9～17 d小鼠胚胎心连续切片进行免疫组织化学或免疫荧光显色;免疫印迹检测胚龄11、13、15、16d和17d小鼠胚胎心组织中Cx43的含量变化.结果:胚龄9～10 d,仅在左心室腹侧壁及原始小梁最先检测到Cx43弱阳性表达.随着发育,Cx43在心房心室阳性范围逐渐扩展,阳性表达逐渐增强.而在某些特定部位,如窦房结、房室管、房室结和房室束等始终未见Cx43阳性染色.结论:Cx43在胚胎心的时空表达模式与心工作心肌和传导系心肌的发育及兴奋传导功能相适应.     

房室结折返性心动过速与冠状窦及后延伸连接蛋白43表达的关系

目的:探讨房室结折返性心动过速(AVNRT)可能的发生机制。方法:通过电生理检查将新西兰大白兔分为双径路组与非双径路组,以冠状窦及后延伸(PNE)为研究标本,分别做H-E染色及连接蛋白43(Cx43)的免疫组织化学显色。结果:所有标本均可见右后延伸,3例标本可见左后延伸,后延伸Cx43阴性表达,双径路组冠状窦连接蛋白43表达强于左心房。结论:左后延伸构成了左房(二尖瓣环附近)至房室结的传导通路;左后延伸及右后延伸具有慢传导的一些特征;冠状窦可能参与了AVNRT的折返环。     

Heterogeneous expression of endothelial connexin (Cx) 37, Cx40, and Cx43 in rat large veins

Gap junctions are clusters of transmembrane protein channels for intercellular communication and are composed of connexin (Cx). The vascular endothelial cells express Cx37, Cx40, and Cx43. We herein examined the spatial distribution of the endothelial connexins Cx37, Cx40, and Cx43 in rat large veins including the cranial vena cava, thoracic section of the caudal vena cava, and abdominal section of the caudal vena cava. We also examined the mean size of the endothelial cells and quantified the protein expression levels of the endothelial connexins. We found that the large veins heterogeneously expressed Cx37, Cx40, and Cx43 as follows: Cx40 > Cx37 > > Cx43 in the cranial vena cava, Cx37 > Cx43 > > Cx40 in the thoracic section of the caudal vena cava, and Cx40 > Cx43 > > Cx37 in the abdominal section of the caudal vena cava. Double immunostaining of two of the endothelial connexins revealed that the gap-junction plaques were composed of various combinations of endothelial connexins. The mean size of the endothelial cells was large, moderate, or small in the cranial vena cava, the abdominal section of the caudal vena cava, or the thoracic section of the caudal vena cava, respectively. The heterogeneity of the endothelial cells of the rat large veins in terms of the connexin expression suggests that the endothelial cells are differently coupled in the large veins. The present data are useful for investigating, for example, disease-related alterations in expression of endothelial connexins in large veins.     

间隙连接蛋白43在舌黏膜癌变过程中的表达

目的 研究间隙连接蛋白43(connexin 43,Cx43)在口腔黏膜癌变过程中的表达变化,探寻其与口腔黏膜癌变的关系及意义.方法 用4亚基硝氧喹啉(4-nitroquinoline-1-oxide,4NQO)诱导SD大鼠口腔黏膜癌变,应用免疫组化方法检测Cx43在口腔黏膜癌变过程中各阶段的动态变化,分析Cx43与口腔黏膜癌变的关系.结果 Cx43蛋白主要表达于大鼠舌黏膜上皮细胞的胞膜、上皮基底层、棘层和颗粒层呈阳性染色,角质层未见表达.随着舌黏膜上皮异常增生程度的增加,Cx43的表达明显下降.在口腔鳞状细胞癌组织中,Cx43染色分布于癌细胞胞质以及鳞癌组织的角化珠内.Cx43在正常舌黏膜、轻度上皮异常增生、中度上皮异常增生、重度上皮异常增生、口腔鳞癌组织中阳性表达率分别为100.00％(10/10)、85.71％(12/14)、66.67％(8/12)、40.00％(4/10)、33.33％(4/12),差异有统计学意义(P＜0.05).结论 4NQO诱发舌黏膜癌变的过程中,Cx43蛋白表达水平随病变程度加重而显著下降,提示Cx43表达异常参与了口腔黏膜的癌变过程.Cx43表达下降是口腔黏膜癌变的早期事件.     

Altered expression of connexin43 and phosphorylation connexin43 in glioma tumors

In this study, we aim to evaluate the connexin (Cx43) and phosphorylation Cx43 (p-Cx43) expression of human glioma tumors and correlate their expression with degrees of malignancy and proliferation, apoptosis, and migration activity of tumors. Cx43 and p-Cx43 expression were examined by Western blot analysis and immunohistochemical staining. The U251 cell viability was measured by MTT analysis. The apoptosis and migration were also evaluated by flow cytometric analysis and fluoroblok transwell chambers, respectively. We found that the Cx43 expression were significantly downregulated in in malignant glioma (WHO grade III and IV), compared to the malignant glioma (WHO grade I and II) and the p-Cx43 expression levels of malignant glioma (WHO grade III and IV) were significantly increased (P<0.05), compared to the malignant glioma (WHO grade I and II) at immunohistochemical analysis. After treatment of cells with a specific inhibitor of PKC, MAPK, and PTK inhibitors, the cell viability and migration were significantly decreased, while the apoptosis was slightly induced. In conclusion, the Cx43 expression level is inversely correlated with the tumor grade and proliferation and migration activity of tumor. Higher p-Cx43 expression level in high tumor grade suggests that a complex mechanism is involved in the suppression of tumor growth by connexins.     

Functional gap junctions in thymic epithelial cells are formed by connexin 43

A multiparametric study was carried out to investigate the presence and possible role of communicating junctions in the thymus, particularly in the thymic epithelium, the major component of the thymic microenvironment. The presence of direct cell-cell communication mediated by gap junctions was demonstrated in human and murine thymic epithelial cells (TEC) by means of in situ and in vitro immunohistochemical labeling as well as in vitro fluorochrome injection and double whole-cell patch clamp experiments. Moreover, both immuno- and Northern blot studies revealed that the gap junction protein connexin 43 and its mRNA were present in TEC. Importantly, we showed that thymic endocrine activity, as ascertained by thymulin production, could be specifically downmodulated in vitro by a gap junction inhibitor, octanol. We also investigated the existence of gap junctions between TEC and thymocytes. In thymic nurse cells we were able to detect cell-cell communication, although only a minor percentage of epithelial/thymocyte pairs were coupled in a given moment. In contrast, intercellular communication was not detected between cultured phagocytic cells of the thymic reticulum and the respective rosetting thymocytes. We suggest that gap junctions formed by connexin 43 may represent a novel (and rather cell type-specific) pathway for intrathymic cellular communication, including TEC/TEC as well as possible TEC/thymocyte interactions.     

Ischaemia-induced temporal expression of connexin43 in rat heart

 To investigate the regulation of cell-to-cell coupling in myocardial ischaemia, the three-dimensional expression of connexin43 (Cx43) during experimental ischaemia was examined using a confocal laser scanning microscope. After induction of myocardial infarction in rats, serial optical sections were obtained from the left ventricular myocardium at various times (3 h to 60 days after ligation). The expression of Cx43 was detected immunohistochemically with FITC-labelled anti-rat Cx43 antibody. Fluorescent dots of Cx43 remained along the intercalated disc and decreased in number around the infarct up to 12 h after ligation. Cx43-expression disappeared completely within 48 h after ligation. After day 4, and especially on days 8 and 15 after ligation, the edges of the cardiomyocytes bordering the infarcted area manifested numerous sarcoplasmic tentacles that reacted positively to anti-desmin antibody. Distinct expression of Cx43 was observed extensively on the tentacles, although no cardiomyocytes remained viable around them. By day 60 after ligation, atypical expression of Cx43 had disappeared. These findings suggest that ischaemia induces temporally abnormal expression of Cx43, which might be responsible for abnormal conduction around the infarct. Received: 4 April 1997 / Accepted: 19 June 1997     

新生儿心肌连接蛋白43、45的表达

目的　研究新生儿心肌不同部位连接蛋白 4 3、4 5 (Cx4 3、Cx4 5 )表达的差异。方法　应用SP免疫组化方法 ,分析和比较 6例新生儿心不同腔室心肌细胞Cx4 3、Cx4 5的表达。结果　 1 新生儿心肌Cx4 3的蛋白表达在心四个腔均有表达 ,呈斑点状遍布于整个心房肌和心室肌的细胞质内和细胞膜表面 ,少数位于闰盘处 ;Cx4 3、主要在心室肌表达 ,心房较少 ;2 Cx4 3与Cx4 5的分布类似 ,但远少于Cx4 3。结论　Cx4 3主要分布于新生儿心肌细胞质内和细胞表面。心室表达多于心房 ,Cx4 5和Cx4 3分布相似 ,但不如Cx4 3丰富。     

Immunohistochemical localization of connexin 43 in the developing tooth germ of rat

Distribution of gap junction protein in maxillary tooth germs of 1-day-old rats was examined by immunohistochemistry, using an affinity-purified antibody specific to residues 360–376 of rat connexin (CX) 43. In 1-day-old rats, the maxillary second molar formed the shape of the cusp, but neither dentine nor enamel was formed between the cells of the dental papilla and the inner enamel epithelium. In the tooth germ, CX 43 was expressed in the cells of the stratum intermedium and the inner enamel epithelium. Labelling in the stratum inter-medium was extensive and showed an increasing gradient from peripheral to cuspal regions. CX 43 detected in the inner enamel epithelium was at cell surfaces facing the interface between the dental papilla and the inner enamel epithelium. The cells of the dental papilla and the inner enamel epithelium began differentiation as odontoblasts and secretory ameloblasts respectively, in the cusps of the first molars, where predentine and dentine were formed but enamel matrix was not secreted. CX 43 was present in the stratum intermedium, inner enamel epithelium, preodontoblasts, odontoblasts and subodontoblasts. The incisors showed the most advanced stage of development, where the enamel matrix and calcified dentine were formed in the labial part of the teeth. The CX 43 epitope was seen in the stratum intermedium, inner enamel epithelium, preameloblasts, preodontoblasts, odontoblasts, and subodontoblasts. Immunolabelling was more extensive in the stratum intermedium and subodontoblasts than in preameloblasts, preodontoblasts, and odontoblasts. The immunolabelling in preameloblasts and preodontoblasts was accumulated at cell surfaces facing the predentine. Further, the labelling in preameloblasts and preodontoblasts disappeared or was reduced at the initiation of enamel matrix secretion and calcification of dentine matrix.The present results suggest that gap junctional cell communication has important roles in tooth development. Further, the extensive CX 43 expression in the stratum intermedium and the subodontoblast layer suggests that gap junctions have an important role in amelogenesis and dentinogenesis.     

实验性病毒性心肌炎组织中连接蛋白43和结蛋白的表达

目的 了解病毒性心肌炎时心肌细胞连接蛋白４３和结蛋白表达情况,以探讨病毒性心肌炎时心律失常的机制。方法 应用免疫组织化学ＳＡＢＣ法,对实验性病毒性心肌炎小鼠心肌细胞连接蛋白４３和结蛋白的表达进行了观察。结果 连接蛋白４３和结蛋白在正常小鼠心肌闰盘中定位分布,均匀存在,后者还在肌节横纹中显示阳性;病毒性心肌炎时两者的表达明显减弱甚至阴性。结论 病毒性心肌炎时受累的心肌细胞连接蛋白４３和结蛋白的表达受