INTERSTITIUM-TO-BLOOD MOVEMENT OF MACROMOLECULES IN THE ABSORBING SMALL-INTESTINE
INTERSTITIUM-TO-BLOOD MOVEMENT OF MACROMOLECULES IN THE ABSORBING SMALL-INTESTINE
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DOI：
10.1152/ajpgi.1981.241.1.g31
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发表时间：
1981-01-01
影响因子：
--
通讯作者：
TAYLOR, AE
中科院分区：
文献类型：
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作者：
GRANGER, DN;PERRY, MA;TAYLOR, AE
在猫回肠吸收段和非吸收段，估计了扩散和对流在血浆蛋白通过肠道毛细血管运输中的相对作用。通过稳态淋巴和血浆蛋白浓度、淋巴流量、净粘膜容积流量和现象学运输方程来估计扩散、对流和净蛋白质通量。对流显然占了。在正常和增加的毛细管滤过率下，总净溶质运动的80-90%。当肠毛细血管通过加强跨粘膜水分运动而由过滤血管转变为吸收血管时，蛋白质的对流和弥漫性流动方向相反，即大量血浆蛋白质通过对流从间质向血液流动。吸收过程中毛细血管蛋白渗漏的幅度可能远远大于利用淋巴蛋白通量变化所预测的。在吸收过程中血浆蛋白进出粘膜间质的大量运动可能有利于蛋白质结合的营养物质（如脂肪酸）的去除。
The relative roles of diffusion and convection in the transport of plasma proteins across intestinal capillaries were estimated for absorbing and nonabsorbing segments of cat ileum. Diffusive, convective and net protein fluxes were estimated with steady-state lymph and plasma protein concentrations, lymph flow, net transmucosal volume flow and phenomenological transport equations. Convection evidently accounts for .apprx. 80-90% of total net transcapillary solute movement at normal and increased capillary filtration rates. When the intestinal capillaries are converted from filtering to absorbing vessels by enhancing transmucosal water movement, the convective and diffusive protein fluxes occur in opposite directions, i.e., significant quantities of plasma proteins move from interstitium to blood by convection. The magnitude of the capillary protein leakage during absorption is probably far greater than predicted using lymphatic protein flux changes. The massive movement of plasma proteins into and out of the mucosal interstitium during absorption may be advantageous for the removal of protein-bound nutrients (e.g., fatty acids).