Permeability characteristics of the human small intestine.
Permeability characteristics of the human small intestine.
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人体小肠的通透性特征。
DOI：
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发表时间：
1965
影响因子：
15.9
通讯作者：
§. Johnkinney
中科院分区：
文献类型：
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作者：
J. S. Fordtran;JR FLOYD C. RECTOR;Maynard F. EWTONt;Nicholas Soter;§. Johnkinney
关于小肠粘膜细胞膜结构的资料相对较少。Hdber和Hober（1）以及Schanker、Tocco、Brodie和Hogben（2，3）研究了大鼠对多种物质的吸收，发现吸收率随脂溶性增加而增加。由此推断，粘膜细胞膜本质上是类脂质的，并且脂溶性物质通过溶解在细胞膜中而被吸收。然而，多年来人们已经知道，小分子虽然不溶于脂质，但也可以从胃肠道吸收。这导致了一种假设，即虽然基本上是类脂状的，但细胞膜上散布着充满水的孔，小分子可以通过这些孔扩散。Hbber和Hdber（1）通过将非脂溶性物质的吸收速率与其分子大小相关联，在大鼠小肠中验证了这一假设。他们的结果支持了这样的论点，即这些分子通过充满水的孔隙扩散被吸收，因为小分子比大分子吸收得更快，并且超过一定尺寸（分子量约180，对应于约4 A的分子半径）没有渗透发生。Lindemann和所罗门的研究（4）是非常一致的，因为他们通过一种独立的方法实验测定了大鼠空肠细胞腔表面的孔径
Relatively little information is available concerning the membrane structure of the mucosal cells of the small intestine. Hdber and Hober (1) and Schanker, Tocco, Brodie, and Hogben (2, 3) studied the absorption of a variety of substances in rats and found that absorption rate increased as lipid solubility increased. From this it has been deduced that mucosal cell membranes are lipoid in nature and that lipid-soluble substances are absorbed by dissolving in the cell membrane. However, it has been known for many years that small molecules, although lipid insoluble, can also be absorbed from the gastrointestinal tract. This has led to the hypothesis that, although essentially lipoidal, cell membranes are interspersed with water-filled pores, through which small molecules can diffuse. Hbber and Hdber (1) tested this hypothesis in the small intestine of the rat by correlating the absorption rate of nonlipid-soluble substances with their molecular size. Their results support the thesis that these molecules are absorbed by diffusion through water-filled pores, since small molecules were absorbed more rapidly than larger ones, and beyond a certain size (molecular weight about 180, which corresponds to a molecular radius of about 4 A) no penetration occurred. Lindemann and Solomon's studies (4) are in close agreement, since they experimentally determined, by an independent method, the pore radius of the luminal surface of the rat jejunal cells