大鼠大脑中动脉超微结构的衰老性变化

目的 研究大脑中动脉超微结构的增龄变化，为探索脑血管疾病的发病机制提供参考资料。方法 应用透射电镜观察各年龄组大鼠大脑中动脉的超微结构。结果 老龄组大鼠大脑中动脉基膜增厚，内弹性膜变薄、不均质、边缘伸出分支到中膜，内皮细胞和平滑肌细胞向内弹性膜穿过，内弹性膜内出现脂质，并有分层、断裂现象，胶原纤维增多。结论 随着年龄的增加，大鼠大脑中动脉的超微结构具有明显的改变。     

大鼠大脑中动脉的衰老性变化

目的：观测大鼠大脑中动脉的衰老性变化。方法：在常规光镜、透射电镜下观察，并应用图像分析系统作测量。结果：衰老后，大鼠大脑中动脉管壁厚度几乎无改变，管腔增大；平滑肌细长，内弹性膜变薄、断裂、分层及脂质沉积。结论：高龄大鼠大脑中动脉管壁的形态和超微结构都具有显著的衰老性改变。     

大白鼠颈总动脉内弹性膜的年龄变化

本文应用光镜、透射电镜对内弹性膜的年龄变化进行定性分析,结果发现:随增龄,内弹性膜变薄,管腔面出现放射状变性,内弹性膜断裂、复制;其内弹性纤维的周围部减少甚至消失;内皮细胞、中膜平滑肌细胞穿过内弹性膜的现象增多。     

大鼠大脑中动脉弹性纤维的构筑与分布

目的 研究大脑中动脉弹性纤维的构筑及分布。方法 采用Weigert染色方法显示弹性纤维，光镜观察大鼠大脑中动脉弹性纤维的构筑与分布；透射电镜观察弹性纤维的超微结构。结果 大鼠大脑中动脉的弹性纤维构成一完整的、波浪状的内弹性膜，着色均匀，中膜、外膜仅有散在的弹性纤维分布，缺乏完整的外弹性膜；电镜下可见内弹性膜规则，均质，厚度均一，边缘光滑、清晰。结论 大鼠大脑中动脉弹性纤维形成完整的内弹性膜，这可能对脑组织具有一定的保护作用。     

低氧对肺动脉平滑肌和内皮细胞蛋白激酶C α mRNA表达的影响

目的：探讨低氧对肺动脉平滑肌和内皮细胞蛋白激酶C(PKC)αmRNA表达的影响。方法：应用原位杂交技术了大鼠不同节段肺动脉平滑肌细胞和内皮细胞PKCαmRNA的分布及低氧对在体和离体肺动脉平滑肌细胞及内皮细胞PKCαmRNA表达的影响。结果：正常大鼠各级肺动脉平滑肌细胞和内皮细胞均有PKCαmRNA的表达,腺泡内肺动脉平滑肌细胞中的表达明显高于肌型肺动脉（P＜0．01）,低氧14d和28d肌型动脉和腺泡内肺动脉内皮细胞的表达均明显增高（P＜0．01）,腺泡内腺动脉平滑肌细胞的表达较对照组明显升高（P＜0．01）,低氧14d肌型肺动脉平滑肌细胞表达升高不明显,但低氧28d明显升高（P＜01）,正常条件下离体培养猪肺动脉平滑肌细胞和内皮细胞均有PKCαmRNA的表达,低氧1h对其表达无明显影响,48,72h表达明显升高,以72h升高最显著（P＜0．001）,结论：低氧可促进肺动脉平滑肌细胞和内皮细胞PKC amRNA 的表达,而以腺泡内肺动脉平滑肌细胞的变化最明显,PCKα在低氧性肺动脉高压的形成中可能起一定作用。     

不同年龄的正常和高血压大鼠脑动脉内弹性膜的变化

运用图像分析仪、光镜和电镜，对不同年龄组的４０只自发性高血压和１９只京都纯种大鼠的脑动脉内弹性膜（Ａ１）、管壁（Ａ２）和管腔（Ａ３）进行了观察测定，发现高血压鼠和正常鼠比较，脑动脉最显著的变化表现为：内弹性膜变薄、折叠减少，部分断裂以及中膜平滑肌的退变，内弹性膜与管壁的比值（ＲＡＴＥ，即Ａ１／Ａ２）显著减小（Ｐ＜０．０１），而壁与腔的比（ＲＡＴＥ２，Ａ２／Ａ３）无显著变化。前者可能与高血压脑血管脆     

大鼠大脑中动脉原弹性蛋白mRNA表达的增龄变化

目的 :检测各年龄组大鼠大脑中动脉原弹性蛋白mRNA表达的变化。方法 :原位杂交染色 ,常规光镜观察 ,图像分析 :结果 :大鼠大脑中动脉的内膜、中膜和外膜均有原弹性蛋白mRNA的表达 ,随年龄增加 ,表达显著减弱。结论 :原弹性蛋白mRNA表达减弱可能是弹性纤维含量随增龄而减少的主要原因之一 ,与老年性脑血管疾病关系密切。     

L-精氨酸对高肺血流量大鼠肺动脉平滑肌细胞增殖与凋亡的影响

探讨L－精氨酸（L－Arginine,L-Arg）对高肺血流量所致肺动脉高压平滑肌细胞增殖与凋亡的干预作用。18只雄性SD大鼠随机分为对照组、分流组和分流＋L精氨酸（L－Arg）组。对分流组和分流＋L－Arg组大鼠行腹主动脉－下腔静脉分流术。观察术后11周大鼠肺动脉平均压（mPAP)和右心室肥厚的改变，采用免疫组织化学方法研究肺动脉平滑肌细胞PCNA和Fas的表达，并通过原位缺口末端标记方法（TUNEL）检测大鼠肺动脉平滑肌细胞的凋亡。结果表明分流组大鼠mPAP、右心室（RV）与左心室加室间隔（LV＋S）的比值，肺中、小型动脉平滑肌细胞增殖指数（PI），凋亡指数（AI），PI／AI比值明显高于对照组大鼠（P＜0．05），同时，分流后肺动脉平滑肌细胞Fas表达增高。然后，分流＋L－精氨酸组大鼠mPAP、RV／LV＋S明显低于分流组（P＜0．05及0．01）。并且L－Arg减少了肺中、小型动脉平滑肌细胞的增殖，促进了凋亡（P＜0．01），wviycL-Arg组大鼠PI／AI比值较分流组明显降低（P＜0．01），同时，L－Arg使分流大鼠肺平滑肌细胞Fas表达明显增强。以上结果提示，L－精氨酸通过抑制肺动脉平滑肌细胞的增殖，促进其凋亡，从而对同肺血流量所致肺动脉高压的形成有重要的调节作用。     

大鼠脊髓前动脉形态及结构成分的增龄变化

目的：观测大鼠脊髓前动脉形态结构的增龄变化。方法：运用透射是及图像分析方法。结果;大鼠脊髓前动脉形态结构的增殖变化主要有管避暑增厚,仙皮细胞变化脱落,内弹性膜变薄、折叠减少,并出现崩解断裂,中膜平滑产生堆集并凸入管腔。随月龄增加,脊髓前动脉生纤维的相对含量显著减少,胶原纤维相对含量显著增加（Ｐ〈０．０１）,血管的Ｃ／Ｅ值也显著增加（Ｐ〈０．０１）。结论：脊髓前动脉形态结构２的老龄变化可能与因管性疾     

γ射线辐射对大鼠胸主动脉平滑肌细胞肾上腺髓质素和内皮素生成的影响

为观察^60COγ射线辐射对培养的大鼠血管平滑肌细胞（VSMC）肾上腺髓质素（Adm)内皮素（ET）生成的影响，以探讨辐射防治再狭窄的机制，采用逆转录－竞争性聚合酶链反应观察经0,1,,24,25Gy辐射的培养大鼠血管平滑肌细胞Adm和ET mRNA水平；用放免方法测定相应的Adm和ET的生成。发现1Gy辐射对VSMC Adm和ET的生成及基因表达均无显著影响。14Gy辐射后VSMC生成的Adm较对照组增加270％（P＜0．05），ET的生成较对照组降低27．3％（P＜0．01）；25Gy辐射使VSMC生成的Adm和ET含量分别增加233％（P＜0．05）和降低58．0％（P＜0．01）。14和25Gy辐射分别使细胞Adm mRNA水平较对照组增加82．4％（P＜0．01）和101％（P＜0．01），使ET mRNA水平较对照组降低47．1％（P＜0．01）及40．2％（P＜0．01）。表明^60Coγ射线辐射可以促进Adm的蛋白及基因表达，而抑制ET的蛋白及基因表达，增加了Adm/ET比值。     

Flow loaded canine carotid artery. II. Ultrastructural changes in the subendothelial layer

To study the subendothelial layer of the flow loaded arteries, blood flow changes were produced by constructing an arterio-venous shunt between the common carotid artery and the external jugular vein using eleven adult beagle dogs. One week after operation, the subendothelial layer of the flow loaded canine carotid arteries was observed with a transmission electron microscope. In the arteries loaded by highly elevated blood flow, the subendothelial layer showed thick subendothelial space (300 to 500 nm) with multilayered basement membrane. The microfilaments and microfibrils increased significantly. There were no collagen fibers. Spindle to cylindrical elastic fibers appeared in the luminal margin of the internal elastic lamina. On the other hand, in the control arteries, the subendothelial layer was thin (about 50 nm) with scanty basement-membrane-like material. There were a few microfilaments and microfibrils, but no collagen fibers. The luminal margin of the internal elastic lamina was smooth. It is suggested that these are the wall shear stress dependent subendothelial changes, which would be partly due to the increased protein synthesis by the endothelial cells stimulated by the wall shear stress and be partly due to the wall shear dependent mechanical stress transmitted from the endothelial surface.     

FLOW LOADED CANINE CAROTID ARTERY II. Ultrastructural Changes in the Subendothelial Layer

To study the subendothelial layer of the flow loaded arteries, blood flow changes were produced by constructing an arterio-venous shunt between the common carotid artery and the external jugular vein using eleven adult beagle dogs. One week after operation, the subendothelial layer of the flow loaded canine carotid arteries was observed with a transmission electron microscope. In the arteries loaded by highly elevated blood flow, the subendothelial layer showed thick subendothelial space (300 to 500 nm) with multilayered basement membrane. The microfilaments and microfibrils increased significantly. There were no collagen fibers. Spindle to cylindrical elastic fibers appeared in the lumlnal margin of the internal elastic lamina. On the other hand, in the control arteries, the subendothelial layer was thin (about 50 nm) with scanty basememt-membrane-like material. There were a few microfilaments and microfibrils, but no collagen fibers. The luminal margin of the internal elastic lamina was smooth. It is suggested that these are the wall shear stress dependent subendothelial changes, which would be partly due to the increased protein synthesis by the endothelial cells stimulated by the wall shear stress and be partly due to the wall shear dependent mechanical stress transmitted from the endothelial surface.     

Fiber arrangement of the rat splenic capsule with special reference to elastic fibers

The fiber arrangement of the rat splenic capsule was examined under scanning electron microscope (SEM) after selective removal by chemical maceration of capsule components, in conjunction with examination of thin sections using a transmission electron microscope (TEM). TEM findings were compared to those of the guinea-pig, mouse and dog. Serosal cells of the rat splenic capsule showed labyrinthic channels that consisted of expanded intercellular spaces and tunnel-like spaces or slits in the basal cytoplasm. The channels contained fascicles of collagenous fibrils, forming a loose net on an underlying elastic lamina of densely aggregated elastic fibers. The fibrous tunica was an intermingled layer of elastic and collagenous fibers and sparse interstitial cells. The fibrous components were arranged more densely in the external layer than in the internal layer of the capsule. The elastic lamina comprised the outermost layer of the fibrous tunica in the intertrabecular region, but was situated deep in the trabecular region. Outward branches of the lamina in the trabecular region were arranged in a spiral. Intrachannel fibrillar fascicles were continuous, via fenestrations in the elastic lamina, with thick fascicles of collagenous fibers. The elastic lamina may play a role in effective contraction of whole spleen. In the guinea-pig, mouse and dog, elastic fibers were fragmented and not arranged in laminae. Typical smooth muscle cells were abundant in the dog. The channel spaces in the serosal tunica are discussed from the viewpoint of extravascular lymphatic flow for circulation of the peritoneal serous fluid.     

狗股动脉弹性纤维的扫描电镜观察

用甲酸消化法制取正常股动脉弹性纤维标本，冷冻干燥后进行扫描电镜观察。见到内弹性膜上有许多散分布的窗孔，中膜的弹性经组织呈复杂的网状，外膜的弹性组织以粗大的纵向分层排列的弹性纤维为主。     

Comparison of the endothelial surface and subjacent elastic lamina of anterior descending coronary arteries at the location of atheromatous lesions with internal thoracic arteries of the same subjects: a scanning electron microscopic study

AIM: Current theories fail to explain the localisation of atheromatous lesions or their variable incidence in different arteries of the same subject. The objective of this study was to compare by scanning electron microscopy (SEM) the endothelial surface and the subjacent elastic lamina of human coronary arteries at the location of areas showing infiltration by lipid and cells, with the same components of internal thoracic arteries of the same subjects. METHODS: The endothelial surface and the subjacent elastic lamina of localised atheromatous areas of 146 anterior descending coronary arteries were compared with the same structural components of the internal thoracic arteries of the same subjects, using SEM, transverse paraffin sections and freeze-fracture. Some arteries were digested with formic acid to destroy the endothelium and interstitial tissue, and reveal the elastin fibre structure of the elastic laminae. RESULTS: Coronary arteries showed localised defects of the endothelial surface and of the elastin fibre structure of the subjacent elastic membrane, with the presence of lipid and cells in transverse sections of the intima. Internal thoracic arteries showed such changes only rarely, more particularly in older age groups. CONCLUSIONS: In localised areas of the coronary arteries showing infiltration of the wall by lipid and cells, there were imperfections of the endothelial surface and of the elastin fibre structure of the subjacent elastic lamina. These imperfections were not in general present in the endothelial surface, or subendothelial elastic lamina of the internal thoracic arteries in age groups below 50, and only rarely in older subjects.     

Scanning electron microscopy of an elastic fiber network which forms the internal elastic lamina in canine saphenous vein

Scanning electron microscopy (SEM) was used to study the arrangement of elastic fibers in the canine saphenous vein as the basis for further studies of veins used in by-pass grafting operations. The elastic fiber arrangement in distended and non-distended veins was examined in both immersion-fixed and perfusion-fixed vessels. Transmission electron microscope (TEM) observation of the SEM samples confirmed the identity of these fibrillar structures as elastic fibers. In addition, specific stains for elastic fibers (Verhoeff's iron hematoxylin and orcein) were used. The elastic fibers forming the internal elastic lamina were arranged in a fishnet-like pattern. Large-diameter fibers, running longitudinally along the vascular wall, were interconnected by smaller oblique fibers. Together the fibers formed an elastic cylindrical network between the endothelium and the smooth muscle cells. The thicker longitudinal fibers were the same diameter in distended and non-distended veins. By contrast, the oblique fibers were thinner and more complexly branched in distended veins. The architecture of the elastic fiber network contributes to vascular flexibility and allows circumferential distension. The interconnecting oblique fibers presumably serve to distribute internal pressure equally around the venous wall.