HETEROPOROSITY OF THE CAPILLARY WALL AS INDICATED BY CINEMATOGRAPHIC ANALYSIS OF THE PASSAGE OF DYES
HETEROPOROSITY OF THE CAPILLARY WALL AS INDICATED BY CINEMATOGRAPHIC ANALYSIS OF THE PASSAGE OF DYES
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染料通过的电影摄影分析表明毛细管壁的异质性
DOI：
10.1111/j.1749-6632.1964.tb52544.x
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发表时间：
1964
影响因子：
5.2
通讯作者：
E. Landis
中科院分区：
文献类型：
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作者：
E. Landis
本简要说明的目的是比较和对比快速扩散染料与缓慢扩散染料通过血管壁的时间、方式和位置。生理学家通过测量分子的过滤、吸收和扩散，深入研究了一些较易接近的组织中的毛细血管渗透性，这些分子的大小从水到蛋白质到葡聚糖。从这类定量数据中，再加上一些合理的假设，生理学家计算出了可能与实际测量的扩散和过滤相一致的孔径的大小和数量。关于毛细血管壁开口的形态和确切位置，这种类型的生理测量允许推论，但不能得出结论。对于电子显微镜工作者来说，情况正好相反。电子显微镜可以处理各种各样的固定组织，其中许多组织还无法进行生理学测量，电子显微镜可以非常详细地描述空隙、间隙、空泡和基底膜的形态和位置。对他们来说，必须推断的是交换的体积或质量。从电子显微照片中特别难以确定的是，给定的开口或囊泡与特定分子交换速率的生理相关性。在这两种方法之间，我们发现了一种更古老的中间方法来研究毛细血管壁的性质;即观察染料的通过，这些染料是根据其化学特性和分级的物理扩散性而选择的。例如，Schulemann在1917年对酸性染料得出结论，它们通过毛细管壁的相对扩散性与通过明胶的相对扩散性相似。在1927年，Landis对灌注染料的单个毛细血管进行的显微注射研究表明，染料在任何一个毛细血管中的通过经常是斑点状的，并且通常在毛细血管之间是不相等的，即使这些血管起源于同一个小动脉。毛细血管壁外的灌注染料出现的时间似乎取决于几个因素，包括染料的胶体性质，毛细血管血压和毛细血管血流量。1930年，劳斯、吉尔丁和史密斯发现，当静脉注射高度扩散的染料（如专利蓝V）时，它们会迅速从哺乳动物肌肉的毛细血管中逃逸出来，速度之快，甚至在染有染料的血液到达静脉末端之前，毛细血管动脉末端周围的组织就被染色了。相反，当使用缓慢扩散的染料时，他们发现染料的第一个血管外外观在微小血管系统的静脉部分之外。由此，他们假设存在毛细血管渗透性梯度，这意味着微血管壁在小动脉附近相对不渗透，但随着接近小静脉和静脉，渗透性变得越来越强。专利蓝V通过真毛细血管壁的一般通道与单个毛细血管的显微注射研究所证实的液体过滤和吸收的同样一般分布是一致的。2另一方面，缓慢扩散染料的顺时针方向通道仍然是一个谜。4人们常常忘记，这种所谓的渗透性梯度是一种渗透性梯度。
The purpose of this brief account is to compare and contrast the passage of a rapidly diffusible dye with that of a slowly diffusible dye through the walls of blood vessels with respect to time, manner, and location. Physiologists have studied capillary permeability intensively in some of the more accessible tissues by measuring filtration, absorption, and diffusion of molecules which, have ranged in size from water through proteins to dextrans. From quantitative data of this sort, and with some plausible assumptions, physiologists have calculated the sizes and numbers of apertures that might be compatible with the diffusions and filtrations that have actually been measured. With respect to the morphology and exact locations of openings in the capillary wall, physiological measurements of this type permit inferences, but not conclusions. For electron microscopists the situation is reversed. Working with a great variety of fixed tissues, many of them inaccessible as yet to physiological measurements, electron microscopists can describe in great detail the morphology and locations of interstices, gaps, vacuoles, and basement membranes. For them, it is the volume or mass ot exchange that must be inferred. Especially difficult to establish from an electron micrograph is the physiological relevance of a given opening or vesicle to the rate of exchange for a specific molecule. Between these two approaches, we find a much older, and intermediate, method of studying the nature of the capillary wall; namely, observing the passage of dyes chosen for their chemical characteristics and for their graded physical diffusibility. For instance, Schulemann' in 1917 concluded for acid dyes that their relative diffusibility through the capillary wall was similar to that through gelatin. In 1927 microinjection studies by Landis2 of dye-perfused single capillaries indicated that dye passage was frequently spotty in any one capillary and usually unequal from capillary to capillary, even when these vessels originated from the same arteriole. The time for appearance of a perfused dye outside the capillary wall seemed to depend on several factors, including the colloidal nature of the dye, capillary blood pressure, and capillary blood flow. In 1930 Rous, Gilding, and SmithS found that when highly diffusible dyes, such as patent blue V, were injected intravenously, they escaped rapidly from the capillaries of mammalian muscle,-so rapidly, indeed, that the tissues surrounding the arterial end of the capillary were colored even before the venous end was reached by the dye-stained blood. Conversely, when slowly diffusible dyes were used, they found the first extravascular appearance of dye outside the venous portion of the minute vessel system. From this they postulated the existence of a gradient of capillary permeability, by which they meant that the walls of minute vessels are relatively impermeable near the arterioles, but become increasingly permeable as the venules and veins are approached. The generalized passage of patent blue V through the walls of true capillaries was compatible with the equally general distribution of filtration and absorption of fluid as demonstrated by microinjection studies of single capillaries.2 On the other hand, the venously oriented passage of slowly diffusible dyes has remained an enigma.4 It is often forgotten that this so-called gradient of permeability a p