QUANTITATIVE FLUORESCENCE MICROSCOPY ON SINGLE CAPILLARIES - ALPHA-LACTALBUMIN TRANSPORT
QUANTITATIVE FLUORESCENCE MICROSCOPY ON SINGLE CAPILLARIES - ALPHA-LACTALBUMIN TRANSPORT
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DOI：
10.1152/ajpheart.1987.252.1.h188
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发表时间：
1987-01-01
影响因子：
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通讯作者：
ADAMSON, RH
中科院分区：
文献类型：
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作者：
HUXLEY, VH;CURRY, FE;ADAMSON, RH
我们已经扩大了使用显微镜密度测定技术[上午。J. Physiol.245（Heart Circ.生理学14）：H495-H505，1983]来测量荧光标记的溶质在蛙肠系膜的单个灌注毛细血管中的溶质渗透系数（Pa）。该方法能够在已知确定溶质和水流过毛细管壁的力的条件下测量大于10，000 mol wt的溶质的跨毛细管通量。α-乳白蛋白（mol wt 14，176，Stokes半径2.02 nm）的Pa从毛细管压力为3.0 cmH 2 O（无净过滤）时的平均值2.1 × 10 - 6 cm/s增加到毛细管压力为15 cmH 2 O时的大于4.0 × 10 - 6 cm/s。取α-乳白蛋白的溶剂阻力反射系数值为0.35，我们得出结论，增加的溶质通量表示通过水通道的溶剂阻力，水力传导率为3.6 X 10（-7）cm X s-1 X cmH 2 O-1。我们的数据符合以下假设，即α-乳白蛋白通过限制性扩散和溶剂阻力在携带90%的跨毛细血管水流（主要水途径）的途径中跨毛细血管壁运输。已经进行了体外和体内校准实验以测试所测量的荧光强度与光度计的测量窗口中的荧光分子的数量成比例的假设。
We have extended the use of a microscope densitometric technique [Am. J. Physiol. 245 (Heart Circ. Physiol. 14): H495-H505, 1983] to measure the solute permeability coefficients (Pa) of fluorescently labeled solutes in single perfused capillaries of frog mesentery. The method enables the transcapillary flux of solutes larger than 10,000 mol wt to be measured under conditions where the forces that determine both solute and water flows across the capillary wall are known. The Pa for alpha-lactalbumin (mol wt 14,176, Stokes radius 2.02 nm) increased from a mean value of 2.1 X 10(-6) cm/s when capillary pressure was 3.0 cmH2O (no net filtration) to greater than 4.0 X 10(-6) cm/s when capillary pressure was 15 cmH2O. Taking a value of 0.35 for the solvent drag reflection coefficient for alpha-lactalbumin, we conclude that the increased solute flux represents solvent drag through a water pathway with a hydraulic conductivity of 3.6 X 10(-7) cm X s-1 X cmH2O-1. Our data conforms to the hypothesis that alpha-lactalbumin is transported across the capillary wall by restricted diffusion and solvent drag in a pathway that carries 90% of the transcapillary water flow (the principle water pathway). In vitro and in vivo calibration experiments have been carried out to test the assumption that the measured fluorescent light intensity is proportional to the number of fluorescent molecules in the measuring window of the photometer.