Carbon monoxide (CO) and [14C]warfarin were used to measure the preepithelial diffusion resistance resulting from poor luminal stirring (RL) in the constantly perfused rat jejunum at varying degrees of distension (0.05, 0.1, and 0.2 ml/cm). RL was much greater than epithelial cell resistance, indicating that poor stirring was the limiting factor in absorption and that an appropriate model of stirring should accurately predict absorption. A laminar flow model accurately predicted the absorption rate of both probes at all levels of gut distension, as well as the absorption of glucose when RL was the rate-limiting factor in absorption. In contrast, an unstirred layer model would not have predicted that gut distension would have little influence on absorption, and would have underestimated [14C]warfarin absorption relative to CO. We concluded that in the perfused rat jejunum, laminar flow accurately models luminal stirring and an unstirred layer should be considered to be a unit of resistance in laminar flow, rather than a model of luminal stirring.
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机译：一氧化碳（CO）和[14C]华法林用于测量持续扩张的大鼠空肠在不同扩张程度（0.05、0.1和0.2 ml / cm）时由于管腔搅拌不良（RL）导致的上皮扩散前阻力。 RL远大于上皮细胞抵抗力，表明搅拌不良是吸收的限制因素，并且适当的搅拌模型应能准确预测吸收。层流模型可以准确预测两种探针在肠道扩张各个水平的吸收率，而当RL是吸收率的限制因素时，葡萄糖的吸收率也可以预测。相比之下，未搅拌的层模型将无法预测肠扩张对吸收的影响很小，并且会相对于CO来低估[14C]华法林的吸收。我们得出结论，在灌注的大鼠空肠中，层流精确地模拟了腔内搅拌和未搅拌的层应视为层流中的阻力单位，而不是管腔搅拌的模型。
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