DIFFERENTIAL ACTION OF PLASMA AND ALBUMIN ON TRANSCAPILLARY EXCHANGE OF ANIONIC SOLUTE
DIFFERENTIAL ACTION OF PLASMA AND ALBUMIN ON TRANSCAPILLARY EXCHANGE OF ANIONIC SOLUTE
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DOI：
10.1152/ajpheart.1993.264.5.h1428
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发表时间：
1993-05-01
影响因子：
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通讯作者：
THIPAKORN, B
中科院分区：
文献类型：
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作者：
HUXLEY, VH;CURRY, FE;THIPAKORN, B
我们测试了两个假设，以解释与白蛋白相比，在血浆灌流期间，微血管中阴离子溶质与水流动(溶剂阻力)的偶联程度降低。溶剂阻力由水力传导性(L(P))和溶质反射系数(Sigma)共同决定。因此，血浆灌流过程中溶剂阻力的减少一定是Sigma增加(假设1)或L(P)减少(假设2)或两种机制的某种组合的结果。在血浆或白蛋白灌流过程中，通过测量青蛙肠系膜交换微血管中阴离子蛋白α-乳白蛋白的L(P)、西格玛和弥散性溶质通透性(P(SD))来验证这些假说。血浆中溶质对α-乳蛋白的渗透系数(P(S)α-乳蛋白)低于牛血清白蛋白([(P(s)alpha-lactalbumin)plasma/(P(s)alpha-lactalbumin)BSA=0.31+/-0.11，均值+/-SE，n=9)。血浆溶质反射系数为0.69+/-0.02，BSA为0.34+/-0.03(n=7)。灌流液蛋白质组成对L(P)无显著影响(L(P)血浆/L(P)牛血清白蛋白=1.02+/-0.11：n=20)。这些数据得出的结论是，等离子体的作用是赋予阴离子溶质电荷选择性，并在较小程度上改变微血管壁的多孔路径。综上所述，这些结果表明，多孔通道对血浆灌流血管中的大分子通量有重要贡献。
We tested two hypotheses to account for the reduction in coupling of anionic solute to water flow (solvent drag) in microvessels during perfusion with plasma compared with albumin. Solvent drag is determined by both hydraulic conductivity (L(p)) and solute reflection coefficient (sigma). Accordingly, decreased solvent drag during plasma perfusion must be the result of an increase in sigma (hypothesis 1) or reduction of L(p) (hypothesis 2) or some combination of both mechanisms. These hypotheses were assessed by measuring L(p), sigma, and diffusive solute permeability (P(sd)) to the anionic protein alpha-lactalbumin in frog mesenteric exchange microvessels during plasma or albumin perfusion. The solute permeability coefficient to alpha-lactalbumin (P(s)alpha-lactalbumin) was lower during exposure to plasma than bovine serum albumin (BSA) [(P(s)alpha-lactalbumin)plasma/(P(s)alpha-lactalbumin)BSA = 0.31 +/- 0.11 (means +/- SE, n = 9)]. Solute reflection coefficient to alpha-lactalbumin (sigma(alpha-lactalbumin)) was 0.69 +/- 0.02 in plasma and 0.34 +/- 0.03 in BSA (n = 7). L(p) was not significantly influenced by perfusate protein composition (L(p)plasma/L(p)BSA =1.02 +/- 0.11: n = 20). These data lead to the conclusion that the actions of plasma are to confer charge selectivity for anionic solute and, to a lesser extent, modify the porous pathways of the microvessel wall. Taken together, these results indicate that porous pathways contribute significantly to macromolecular flux in plasma-perfused vessels.