普萘洛尔、酚妥拉明对由去甲肾上腺素诱导的家兔肠系膜微血管运动的影响

应用显微录像静画步进法观察家兔肠系膜局部施加去甲肾上腺素（NA）后，诱寻出微动脉周期性、节律性的血管运动及静脉注入普萘洛尔、酚妥拉明对其产生的影响，以期探讨血管运动产生机制及其与α－，β－肾上腺素受体的关系。结果：在家兔颈动脉平均血压为11．40±0．89kPa的条件下，局部施予NA0．8μg于肠系膜观察域，引起微动脉的血管运动，其频率：0．109±0．006Hz，振幅：5．51±0．42μm。同一视野的微静脉和毛细血管未出现血管运动。血管运动的振幅在同一支微动脉上分布不均，呈节段性。普萘洛尔0．1mg／ml·kg-1、0.5mg／ml·kg-1组的内径、血压、血管运动频率及振幅无明显改变，1．0mg／ml·kg-1组的血压无明显变化，内径减小，血管运动频率增加，振幅减小。静脉注入酚妥拉明0．5mg／ml·kg－1及1．0mg／ml·kg-1，颈动脉血压降低，血管内径增加，血管运动频率减少，振幅降低，血管运动被抑制。结论：上述结果表明生理条件下，局部施加NA可以诱导出家兔肠系膜微动脉血管运动，并且血管运动的发生与NA及α－，β-肾上腺素受体有一定关系。     

伴皮质下梗死和白质脑病的常染色体显性遗传性脑动脉病患者脑小动脉的病理学研究

目的探讨伴皮质下梗死和白质脑病的常染色体显性遗传性脑动脉病(CADASIL)患者脑小动脉的硬化程度,比较不同部位、不同节段脑小动脉硬化指数的差异。方法对4例CADASIL患者的脑组织标本(疾病组)及对照组脑组织标本4例,进行平行及垂直于大脑表面方向切片,HE染色后,观察额叶中外径<300μm的小动脉病理学变化,比较疾病组和对照组、穿支动脉及其分支、灰质和白质以及不同节段小动脉的硬化指数(SI)。结果疾病组小动脉内膜下纤维组织增生和透明变性。不同切片方法、不同节段和不同部位比较,疾病组脑小动脉SI均高于对照组,差异有显著意义(P<0.05)。疾病组灰质及白质SI分别为0.36±0.10、0.44±0.17,二者比较差异有显著意义(P<0.05);外径<100μm和>100μm的小动脉SI分别为0.40±0.17、0.37±0.11,二者比较差异有显著意义(P<0.05)。穿动脉主干和分支所得结果相似。结论CADASIL患者存在小动脉狭窄和管壁纤维性增厚,病变主要发生在白质,且以小动脉末端病变较严重。     

A method for direct patch-clamp recording from smooth muscle cells embedded in functional brain microvessels

 The aim of this project was to develop a method to enable routine application of all patch-clamp configurations to smooth muscle cells while they remain embedded in blood vessels. Small blood vessels were isolated from rabbit brain using an enzymatic and mechanical procedure. Vessels were identified under a microscope and the majority were small arterioles with a mean external diameter, in Ca²⁺-containing (1.5 mM) solution, of 29 μm and variable lengths of 100 μm or more. Arterioles excluded trypan blue, constricted in response to 60 mM K⁺ and dilated in response to levcromakalim. Patch-clamp gigaOhm seals were made regularly on smooth muscle cells embedded in arterioles. The membrane potential recorded using amphotericin-B-containing patch pipettes averaged –72 mV. Short arteriolar segments could be voltage-clamped. Injection of depolarising current or bath application of 10 mM Ba²⁺ induced constriction of the entire arteriolar segment. Cell-attached patch, inside-out patch and outside-out patch recordings were made readily and K⁺ channel unitary currents were studied. The method is readily applied and has several advantages over previous methods for the study of ion channels in smooth muscle cells. Notably, avoidance of single-cell isolation means that enzymatic treatment is minimised and cells can be studied within their normal environment of the blood vessel wall. Received: 26 August 1997 / Received after revision and accepted: 17 October 1997     

He-Ne激光照射对大鼠心肌微动脉内皮细胞和心肌组织内皮型一氧化氮合酶表达的影响

目的　探讨He Ne激光照射大鼠心前区对心肌微动脉内皮细胞和心肌组织内皮型一氧化氮合酶 (eNOS)表达的影响。方法　将 12只Wistar大鼠随机分为对照组和激光照射组 ,每组 6只。激光照射组的照射剂量为 6 0 5J cm2 ,每天照射 1次 ,连续 10天。最后一次激光照射后 ,两组大鼠均于左心室前壁取材 ,采用免疫组织化学染色方法 ,观察心肌组织各层eNOS表达的变化。结果　激光照射组eNOS表达的平均光密度值为 0 2 6 3± 0 0 15 ,高于对照组的 0 2 2 7± 0 0 16 (t=17 35 ,P <0 0 1) ;并且在各级心肌微动脉内皮细胞核的一端可见eNOS表达的阳性颗粒 ,而对照组不明显。结论　以剂量为 6 0 5J cm2 的He Ne激光照射大鼠心前区 ,可使心肌微动脉内皮细胞中eNOS的表达增强 ,为阐明He Ne激光照射扩张微血管、改善微循环的作用机制 ,提供了实验形态学依据     

高血压病人小动脉中磷酸化细胞外信号调节激酶1/2及ets样基因1的蛋白表达

目的研究细胞外信号调节激酶系统（ERK）及其下游底物ets样基因1（E1k-1）在原发性高血压中的作用。方法采用免疫组织化学方法，对比观察高血压和非高血压病人胃肠小动脉血管平滑肌细胞及内皮细胞中细胞外信号调节激酶（ERK1／2）和ets样基因1（E1k-1）的磷酸化情况。结果高血压组胃肠小动脉血管平滑肌细胞中磷酸化ERK1／2染色阳性率（8．31％）明显高于非高血压组（0．53％），P〈0．05；高血压组内皮细胞中磷酸化ERK1／2的阳性率（4．97％）明显高于非高血压组（P〈0．05）。高血压组胃肠小动脉血管平滑肌细胞中磷酸化Elk-1染色阳性率（3．53％）明显高于非高血压组（0．27％），P〈0．05。在血管平滑肌细胞、血管内皮细胞中磷酸化ERK1／2与磷酸化E1k-1的表达均有正相关关系。结论原发性高血压患者的胃肠细小动脉血管平滑肌细胞以及内皮细胞中细胞外信号调节激酶及其下游底物Elk-1的磷酸化增加。     

Effects of insulin on the acetylcholine-induced hyperpolarization in the guinea pig mesenteric arterioles

Background: Insulin induces endothelium-dependent vasodilatation, which may be casually related to the insulin resistance and hypertension. Endothelium-derived nitric oxide (NO) is the most important mechanism of insulin-induced vasodilatation, and a possible contribution of endothelium-derived hyperpolarizing factor (EDHF) is also considered. Attempts were made to observe the effects of insulin on acetylcholine (ACh)-induced hyperpolarization in the submucosal arteriole of the guinea pig ileum, the objective being to investigate possible involvement of EDHF in the actions of insulin. Methods: Conventional microelectrode techniques were applied to measure the membrane potential of smooth muscle cells in the submucosal arteriole. EDHF-induced hyperpolarization was elicited by ACh in the presence of both N^ω-nitro- -arginine ( -NNA) (100 μM) and diclofenac (1 μM). Results: The resting membrane potential was −70.9 mV, and Ba²⁺ (0.5 mM) depolarized the membrane to −33.0 mV. Insulin (10 μU/ml to 100 mU/ml) did not change the membrane potential in the absence or presence of Ba²⁺. In the presence of Ba²⁺, ACh (3 μM) hyperpolarized the membrane with two components, an initial large hyperpolarization followed by a slow and small one. Low concentration of insulin (100 μU/ml) did not alter the ACh-induced hyperpolarization. High concentration of insulin (100 mU/ml) shortened the time required to reach the peak amplitude and tended to increase the peak amplitude of the ACh-induced hyperpolarization. Conclusions: The data show that insulin enhances the ACh-induced hyperpolarization in the submucosal arterioles of the guinea pig ileum. The results suggested that EDHF also accounts for one of the endothelial factors involved in the insulin-induced vasodilatation.     

全自动向心分级技术及小动脉优化生长

首先，本文提出一种微机小动脉自动向心分级技术，其次，本文推广，改进了Ｗｏｌｆｇａｎｇ Ｓｃｈｒｎｉｎｅｒ的小动脉空间优化生长模型，提出信号灯追踪，阻力平衡和双准则求新增加管段末端点的新算法，并用这种模型和算法成功地在微机上模拟了缝痘肌小动脉的生长。     

Microvascular Endothelial Cells Exhibit Optimal Aspect Ratio for Minimizing Flow Resistance

A recent analytical solution of the three-dimensional Stokes flow through a bumpy tube predicts that for a given bump area, there exists an optimal circumferential wavenumber which minimizes flow resistance. This study uses measurements of microvessel endothelial cell morphology to test whether this prediction holds in the microvasculature. Endothelial cell (EC) morphology was measured in blood perfused in situ microvessels in anesthetized mice using confocal intravital microscopy. EC borders were identified by immunofluorescently labeling the EC surface molecule ICAM-1 which is expressed on the surface but not in the EC border regions. Comparison of this theory with extensive in situ measurements of microvascular EC geometry in mouse cremaster muscle using intravital microscopy reveals that the spacing of EC nuclei in venules ranging from 27 to 106 μm in diameter indeed lies quite close to this predicted optimal configuration. Interestingly, arteriolar ECs are configured to minimize flow resistance not in the resting state, but at the dilated vessel diameter. These results raise the question of whether less organized circulatory systems, such as that found in newly formed solid tumors or in the developing embryo, may deviate from the optimal bump spacing predicted to minimize flow resistance.     

虎杖甙对大鼠细动脉平滑肌细胞ATP敏感钾通道的影响

目的 :探讨中药虎杖提取物 -虎杖甙扩张休克动物细动脉、改善微循环灌流的作用机制。方法 :应用膜片钳技术的细胞贴附式观察虎杖甙对大鼠肠系膜细动脉平滑肌细胞 ATP敏感钾通道 ( KATP)的影响。结果 :细胞外液加入 0 .2 m mol/L虎杖甙后 ,通道电流幅度无明显改变 ,说明虎杖甙不影响 KATP通道电导 ;但加入虎杖甙后KATP通道动力学发生了明显变化 ,通道开放时间短成分 τ0 1 和长成分τ0 2 增大 ,通道开放时间 Tom延长 ,通道开放概率 Po提高 ,提示KATP通道激活。结论 :虎杖甙具有激活 KATP通道的作用 ,它可能通过使细动脉平滑肌超极化而扩张细动脉 ,从而改善休克动物微循环。