Shibata M, Kamiya A
Institute of Medical Electronics, Faculty of Medicine, University of Tokyo, Japan.
Jpn J Physiol. 1992;42(4):631-9. doi: 10.2170/jjphysiol.42.631.
To examine direct influences of capillary blood flow on its permeability of water-soluble substances, we measured the local capillary permeability in the rabbit tenuissimus muscle at various capillary blood flow levels by the use of microscopic tissue clearance method. After staining the muscle with Cr-EDTA (M.W.: 341) as the test tracer by suffusing its solution around the tissue, subsequent concentration change in the tissue due to the tracer washout by capillary blood flow was measured from the intensity change on the TV monitor through the vital-microscope. The decay constant of obtained tissue clearance curve has been theoretically predicted to be equal to the local capillary permeability surface area product (PS) per unit tissue volume (Vt). The local capillary permeability (P) could be quantified by calculating the capillary surface area (S) from the perfused capillary density in the visualized microscopic field. The calculated values of P and PS/Vt in the high flow state were 6.00 +/- 0.70 (X 10(-6) cm/s) and 5.85 +/- 0.77 (X 10(-4)/s), respectively, which were significantly larger than those in the low flow state (p < 0.01). It was suggested that there was a mechanism in the red cell passage through the capillary which facilitated the substance exchange across the capillary wall.
为了研究毛细血管血流对其水溶性物质通透性的直接影响，我们通过显微组织清除法在兔缝匠肌的不同毛细血管血流水平下测量了局部毛细血管通透性。在用Cr-EDTA（分子量：341）作为测试示踪剂对肌肉进行染色时，将其溶液灌注在组织周围，随后通过活体显微镜从电视监视器上的强度变化测量由于毛细血管血流冲洗示踪剂而导致的组织中示踪剂浓度变化。理论上预测，所获得的组织清除曲线的衰减常数等于单位组织体积（Vt）的局部毛细血管通透性表面积乘积（PS）。通过从可视化显微镜视野中的灌注毛细血管密度计算毛细血管表面积（S），可以对局部毛细血管通透性（P）进行量化。高血流状态下P和PS/Vt的计算值分别为6.00±0.70（×10⁻⁶ cm/s）和5.85±0.77（×10⁻⁴/s），显著高于低血流状态下的值（p < 0.01）。提示在红细胞通过毛细血管的过程中存在一种机制，促进了物质跨毛细血管壁的交换。
