微循环灌流状态的在体研究

本文介绍采用国内外先进的显微高速动态分析装置,定性和定量地检测了毛细血管前括约肌的舒缩运动;细胞流变特性;细胞与微血管的相互作用和动态耦合关系。提示:微循环灌流状态取决于流质与流场的动态耦合关系,且具有复杂性和多变性。而所谓的“海涛式灌注”是不确切的。     

硬化红细胞对微循环灌注的影响

长期来认为由神经体液因子调节的微血管及毛细血管前括约肌的舒缩状态是影响微循环灌流的决定因素。随着血液流变学的发展,对细胞流变性改变在微循环灌注中的重要性予以相当重视;本文用SH-氧化剂diamide造成红细胞膜蛋白交联而致红细胞变形能力降低,大鼠分别交换输注经上述处理的红细胞悬液或正常红细胞悬液,     

缺血再灌注家兔微循环、血液流变性的变化及银杏叶提取物的干预作用

目的：研究缺血再灌注对微循环、血液流变性的影响及银杏叶提取物的干预作用。方法：复制家兔缺血再灌注模型。采用显微电视和微机图像处理系统对家兔球结膜微循环进行定量分析。结果：用药组在缺血30min、再灌注30min等时相，与对照组比较，其微动／静脉口径（3、4级）、微静脉流速／流量、毛细血管条数均增加（P＜0．05），红细胞聚集、白色微小血栓等均减少（P<0．05）。结论：家兔缺血再灌注存在明显微循环障碍，银杏叶提取物有保护微循环的作用。其机制可能与扩血管、改善血液流变学有关。     

再植断指再灌注后微循环损伤的临床观察

目的 探讨断指再植后再植手指微循环损伤的特点及规律。方法 动态检测断指再植后患者血清超氧化物歧化酶(SOD)，观察断指再植后缺血再灌注损伤的变化。用甲襞微循环测定仪动态观察再植手指甲襞毛细血管的扩张、渗出、出血、毁损、再生及微循环血管的血流状况。结果 断指再植后SOD 2周内持续低于正常水平，且于1—6h和24—72h形成两个低峰期。再植断指甲襞微循环恢复血液灌注后经历渗出、结构毁损和结构功能恢复三个时期。结论 断指再植后缺血再灌注损伤至少在两周内持续存在，微循环损伤是再植手指缺血再灌注损伤最重要的部分。     

纳络酮对缺血再灌注心肌微循环血流量及其超微结构变化的影响

本文观察了纳络酮对犬缺血和再灌注心肌微循环血流量及其超微结构变化的影响。结果表明：心肌缺血再灌注时微循环血流量明显降低（P＜0．01），但再灌注早期（5min），心肌微循环血流量接近正常，缺血40min，再灌注30min，毛细血管周围组织严重水肿，内皮高度肿胀，管腔狭窄，甚至闭塞；纳络酮治疗缺血和再灌注早期，心肌微循环血流量明显增加（P＜0．01）；毛细血管周围组织水肿及管腔狭窄程度明显轻于缺血再灌注组。提示：纳络酮可减轻缺血再灌注心肌的水肿程度，增加微循环血量，推迟“无再流现象”的发生。     

牙周炎大鼠毛细血管铸型构建

目的　通过毛细血管灌注的方法,构建Wistar大鼠牙周炎模型的牙周毛细血管铸型,为牙周炎的微循环研究提供形态学方法。 方法　8周龄Wistar大鼠,从左心室的主动脉入口插管灌注颗粒状材料,皮肤肿胀发红灌注结束。灌注材料充分聚合24 h后,用腐蚀方法去除软组织。制成牙周炎的毛细血管铸型标本。S-3000N扫描式电子显微镜观察牙周毛细血管铸型。 结果　成功构建了牙周炎毛细血管铸型模型,在30、2000、4500倍扫描电镜下清晰地观察到了龈缘、龈沟及龈乳突等部位的毛细血管三维空间形态分布与走形。 结论　Wistar大鼠牙周炎的毛细血管铸型成功构建,为牙周炎微循环的研究提供了形态学方法,有助于从不同方面揭示牙周炎的各种病理变化。     

固定对内源性过氧化物酶染色显示脑及脊髓内微血管方法的探讨

脑及脊髓内毛细血管的定量分析是研究微循环动力学变化规律、调节机理以及脑血管疾患的基础。目前多采用向血管腔内灌注填充剂来研究血管构筑及数量。此法操作复杂,灌注液刺激血管壁,压力不易掌握,以至毛细血管易破裂,且填充剂颗粒无法达所有微血管内,易造成充盈不足等。我们根据血液中存在着大量的内源性过氧化物酶可与联苯胺反应产生不溶性沉淀的原理,改良了一种新的微血管染色方法(中华病理学杂志,1992,21∶313)。这种方法能准确地反映出组织内微血管的数量,其关键在于组织的新鲜度和血液的充盈程度,     

葛根素对冠心病患者甲襞微循环及血液流变学的影响

目的评价葛根素对冠心病患者甲襞微循环及血液流变学的作用。方法４３例冠心病患者给予葛根素２００～４００ｍｇ，加入５％葡萄糖２５０ｍｌ静滴每日１次，１０～１４ｄ为１疗程。治疗前后分别检查血液流变学、甲襞微循环及心电图。结果（１）葛根素可明显改善冠心病患者胸痛、胸闷、憋气、心悸等症状及心电图缺血性ＳＴ～Ｔ表现。（２）葛根素可明显降低甲襞微循环各项积分值及总积分值，可使微血管、微血流、微血管周围状态均有明显改善，表现为毛细血管密度增加，输入枝、输出枝口径扩大，流速加快。（３）葛根素可明显降低血液粘度。结论葛根素可显著改善冠心病患者的甲襞微循环、降低血液粘度、减慢心率、降低心肌耗氧量，从而抗心绞痛。治疗冠心病疗效确切、安全。     

微循环障碍与激素性股骨头坏死相关性实验研究

目的 研究激素性股骨头坏死的发病原因。方法 用糖皮质激素诱导出股骨头缺血坏死的兔子模型,对比检测实验组和对照组的微循环状况以及与微循环有关的毛细血管内血液的流速,血液粘滞度,成份改变和病理组织学改变,弄清发病的主要相关因素。结果 实验组毛细血管中红细胞聚集,血液流速明显缓慢;血脂、血浆蛋白含量增高;股骨头内毛细血管数量减少,血管襻迂曲变长。结论 激素性股骨头缺血坏死的发病与微循环障碍有明显的关系。     

血细胞变形／聚集测试仪

血细胞变形／聚集测试仪马跃中王晓坤解放军第４５１医院器械科在血流变学研究中，血细胞变形性和聚集性受到人们愈来愈广泛的重视，血细胞是否有良好的变形能力是决定血细胞能否顺利通过毛细血管，保持微循环正常灌注的必要条件。而血细胞的聚集性则是血液独特的非牛顿性...     

Identification of vascular sphincters at the junction between alveolar capillaries and pulmonary venules of the mouse lung

Background: A peculiar feature of lung circulation in the lung is the pronounced variations in blood volume observed in alveolar capillaries that occur because of the changes in the conformation of the alveolar wall that are associated with the respiratory movements. This phenomenon has led to the postulate that mechanisms of postcapillary control of blood flow are to be present in the lung vessels. In the present study we searched for microanatomical evidence of vascular sphincters in the deep lung tissue of mice, namely in alveolar capillaries and pulmonary veins. Methods: We have used scanning electron microscopy (SEM) to examine two types of samples of normal lung tissue of CD-1 mice: 1) vascular corrosion casts made by vascular perfusion with Mercox® resin, and 2) routinely made gold/platinum-coated replicas of sectioned lung tissue. Results: Careful scrutiny of the vessels of the deep lung tissue led to the identification of sphincters in alveolar capillaries. These sphincters were located at the junction between capillary and pulmonary veins. They corresponded to areas to the vascular wall showing circular swellings where a radial organization was observed, since they were made up of alternating grooves and bulges. Transmission electron microscopy showed that smooth muscle cells participated in the formation of the sphincters. Conclusions: Our data reveal a new location for vascular sphincters in pulmonary vessels and, because these novel sphincters are located at the capillary-vein junction, they offer a structural setting for the existence of postcapillary control of blood flow in the pulmonary circulation of mice. © 1995 Wiley-Liss, Inc.     

Are the precapillary sphincters and metarterioles universal components of the microcirculation? An historical review

The microcirculation is a major topic in current physiology textbooks and is frequently explained with schematics including the precapillary sphincters and metarterioles. We re-evaluated the validity and applicability of the concepts precapillary sphincters and metarterioles by reviewing the historical context in which they were developed in physiology textbooks. The studies by Zweifach up until the 1950s revealed the unique features of the mesenteric microcirculation, illustrated with impressive schematics of the microcirculation with metarterioles and precapillary sphincters. Fulton, Guyton and other authors introduced or mimicked these schematics in their physiology textbooks as representative of the microcirculation in general. However, morphological and physiological studies have revealed that the microcirculation in the other organs and tissues contains no metarterioles or precapillary sphincters. The metarterioles and precapillary sphincters were not universal components of the microcirculation in general, but unique features of the mesenteric microcirculation.     

Mechanicochemical sphincters in the microcirculatory system of the ear

Argyrophilic sphincters ("rings" and "bracelets") are found in the internal vascular network of the ear. They do not contract when treated with myotropic agents or muscle relaxants, nor do they allow the passage of silver ions.Presented by Academician of the Academy of Medical Sciences of the USSR S. A. Sarkisov.Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 70, No. 12, pp. 96–97, December, 1970.     

Microscopy of the living pancreas in situ

The purpose of this investigation was to study the microscopic anatomy of the living pancreas in situ. The results indicate that: (1) it is possible to study cellular detail in the living pancreas with resolution closely approaching the limit of resolution of the light microscope; (2) blood flow through indivdual capillaries in both acinar and islet tissue is intermittent; (3) local blood flow through acinar capillaries is regulated by smooth muscle precapillary sphincters and by endothelial sphincters, while flow through capillaries in islets is regulated locally by endothelial sphincters only: (4) insular-acinar capillary anastomoses exist but are not frequent; (5) secretory canaliculi between adjacent acinar cells exist in life and pass between centro-acinar cells to reach the lumen of the ducts; (6) processes of beta cells may pass between two adjacent cells to provide additional surface area for transcapillary exchange; (7) the formation and release of zymogen granules occurs within 45-90 minutes in acinar cells stimulated with pancreozymin and the formation and release of beta granules occurs within 20-60 minutes in beta cells stimulated with tolbutamide; and (8) cytological changes during the secretory cycle in acinar and beta cells are consistent with the current ultrastructural theory of secretion.     

The valves, baffles and sphincters of the respiratory system.

'Starting with the integument we see many organs are contractile sacs or multiples thereof which tubes or bags constitute the major part of the entire body' (1). The lungs are a collection of these universal contractile chambers connected in chains and bunches. Such containers typically have muscular walls which stretch and contract to fill and empty also valves or sphincters to regulate the flow between neighbouring chambers. The heart, stomach and uterus are familiar examples. In some systems (e.g. the digestive, renal and respiratory tracts) traffic is also between the milieu exterior and the milieu interior through the organ's wall which is part of the integument. These movements from organ to organ or milieu to milieu involve pressure variations generated by the concerted actions of the mural and valvular muscles. A muscle usually has a doppel-g?nger so they are arranged in reciprocating pairs, supinators with pronators, flexors with extensors, chamber walls with sphincters etc.     

The vascular anatomy of the liver of the monitor lizard (genus varanus)

The gross and microscopic anatomy of the vasculature of the monitor lizard liver was studied. The portal vein has a peculiar arrangement of smooth muscle. The tunical media of the entering portal vein has bundles of smooth muscle cells separated by large numbers of collagenous fibers. The amount of smooth muscle decreases as the vessel decreases in diameter and soon one finds intermittent broad, thin bands of smooth muscle. As the caliber of the vessels continues to decrease, the smooth muscle bands become narrower and thicker so that they appear as doughnut-shaped sphincters. The sphincters are usually found at the beginning of each branch of the portal vein as well as along the course of veins between areas of branching. Some sphincters are found in direct contact with the outer capsule of the liver. Sphincters occur in the terminal branches of the portal vein just proximal to the sinusoids. Small numbers of scattered smooth muscle cells were seen arranged longitudinally, obliquely, or circularly in the smaller hepatic veins. Even the large hepatic veins had only small amounts of smooth muscle. At no place along the course of hepatic veins could smooth muscle sphincters equivalent to those seen around portal veins be found. The monitor lizard should be an excellent subject for physiological and pharmacological studies of regulation of intrahepatic portal vein blood flow.     

A novel role of CXCR4 and SDF‐1 during migration of cloacal muscle precursors

The cloaca acts as a common chamber into which gastrointestinal and urogenital tracts converge in lower vertebrates. The distal end of the cloaca is guarded by a ring of cloacal muscles or sphincters, the equivalent of perineal muscles in mammals. It has recently been shown that the development of the cloacal musculature depends on hindlimb muscle formation. The signaling molecules responsible for the outward migration of hindlimb myogenic precursors are not known. Based on the expression studies for CXCR4 and SDF‐1, we hypothesized a role of this signaling pair during cloacal muscle precursor migration. The aim of our study was to investigate the role of SDF‐1/CXCR4 during cloacal muscle precursor migration in the chicken embryos. We show that SDF‐1 is expressed in the cloacal region, and by experimentally manipulating the SDF‐1/CXCR4 signaling, we can show that SDF‐1 guides the migration of CXCR4‐expressing cloacal muscle precursors. Developmental Dynamics 239:1622–1631, 2010. © 2010 Wiley‐Liss, Inc.     

Pulmonary lymphatic filling is increased in spontaneously hypertensive rats

Extravascular lung liquid must rely on tissue-space pressure gradients to drive it into the lymphatics because the fluid is outside the lymphatic contractile pumping and valve control. Focal tissue pressure changes could result from muscular contraction in the blood vessel walls. Perivascular lymphatics usually lie within the adventitia of pulmonary blood vessels, and are generally more noticeable in veins than arteries. Spontaneously hypertensive rats have exaggerated focal pulmonary venous muscle (venous sphincters). These muscular tufts are often near initial lymphatics; if their contraction was important for lymph transport, spontaneously hypertensive rats could have more lymphatic filling in the areas of the pulmonary venous sphincters than normotensive rats. Because the focal muscularity is found in pulmonary veins more than arteries, veins may have more focal lymphatic filling than arteries. To test these hypotheses, lung histology and vascular and lymphatic casts of spontaneously hypertensive and normotensive rats were examined. Contracted venous sphincters were found on 108 of 127 veins with lymphatics in the spontaneously hypertensive rats and 5 of 41 in the normotensive rats P<0.01). The spontaneously hypertensive rats had deeper venous contractions and more lymphatic filling around both arteries and veins (P<0.01). In the hypertensive rats, the venous was greater than the arterial lymphatic filling (P<0.01). On the pleural surface, hypertensive rats also had greater lymphatic filling than controls (P<0.01). This anatomic evidence suggests that pulmonary venous sphincters are associated with focal lymphatic filling, and perivascular muscle action might be a component of the pulmonary lymphatic system.     

Sphincters of the pulmonary veins in man,and their significance

Summary Pressure curves in the pulmonary vein and in the left auricle were recorded in patients with stenosis of the left atrioventricular valve before and after mitral valvotomy. The curves showed that the sphincters of the pulmonary veins may fail when the mean pressure in the left auricle exceeds 20 mm Hg. Normally, by blocking the reverse flow, the sphincters protect the pulmonary vessels from the back pressure wave. With increased pressure in the left auricle, insufficiency of the pulmonary vein sphincters could provoke changes in the small pulmonary vessels, which were demonstrated histologically on biopsy material, and which had the effect of increasing the resistance to blood flow. Auricular fibrillation, by causing the sphincters to become ineffectual even when the hypertension in the left auricle is moderate, may promote a relatively early rise of pulmonary vascular resistance.(Presented by Active Member AMN SSSR V. V. Parin) Translated from Byulleten' Éksperimental'noi Bioligii i Meditsiny, Vol. 51, No. 6, pp. 14–17, June, 1961