Perry M A, Crook W J, Granger D N
Am J Physiol. 1981 Dec;241(6):G478-86. doi: 10.1152/ajpgi.1981.241.6.G478.
The permeability of capillaries in the stomach to small and large solutes was studied with the double-indicator diffusion technique in the dog stomach and by analysis of steady-state lymph and plasma samples in the cat stomach. The effective pore radius in gastric capillaries determined by indicator diffusion was 53 A, whereas steady-state lymph samples predicted a small-pore radius of 47 A. At the highest plasma flow rates studied (achieved by intra-arterial infusion of isoproterenol), indicator diffusion estimates of the permeability-surface area product for raffinose, inulin, and beta-lactoglobulin A were 140, 70, and 8 ml . min-1 . 100 g-1, respectively. The lymph studies indicate that gastric capillaries are more permeable than capillaries in the intestine and colon to albumin and larger molecules. The calculated effective large-pore radius of gastric capillaries was 250 A. The osmotic reflection coefficients (sigma d) ranged from 0.73 +/- 0.03 for albumin to 0.91 +/- 0.02 for beta-lipoprotein (120-A radius). The sigma d for total plasma protein was 0.78 +/- 0.03, indicating a substantial transcapillary oncotic pressure gradient, despite the greater permeability of these capillaries for macromolecules.
采用双指示剂扩散技术在犬胃中以及通过分析猫胃中稳态淋巴液和血浆样本，研究了胃毛细血管对小分子和大分子溶质的通透性。通过指示剂扩散测定的胃毛细血管有效孔径为53埃，而稳态淋巴液样本预测的小孔径为47埃。在所研究的最高血浆流速下（通过动脉内输注异丙肾上腺素实现），棉子糖、菊粉和β-乳球蛋白A的通透表面积乘积的指示剂扩散估计值分别为140、70和8 ml·min⁻¹·(100 g)⁻¹。淋巴液研究表明，胃毛细血管对白蛋白和大分子的通透性高于小肠和结肠的毛细血管。计算得出的胃毛细血管有效大孔径为250埃。渗透反射系数（σd）范围从白蛋白的0.73±0.03到β-脂蛋白（半径120埃）的0.91±0.02。总血浆蛋白的σd为0.78±0.03，这表明尽管这些毛细血管对大分子的通透性较高，但仍存在显著的跨毛细血管胶体渗透压梯度。
