Bosin T R, Hathaway D R, Maickel R P
Am J Physiol. 1975 Feb;228(2):496-500. doi: 10.1152/ajplegacy.1975.228.2.496.
A comparative study of the intestinal transport of DL-tryptophan and its 1-methylindole (tryptophan-l-Me) and benzo[b]thiophene (tryptophan-S) analogs has been carried out in vitro, using the everted intestinal sac of the rat and hamster. Both tryptophan and tryptophan-S are actively transported across the intestine, while tryptophan-l-Me is not actively transported. The active transport of tryptophan is competitively inhibited by tryptophan-S, suggesting a similar carrier, while tryptophan-l-Me is not an inhibitor of tryptophan transport, suggesting little or no interaction with the carrier. The transport of tryptophan and tryptophan-S is depressed at concentrations (10 mM), and all three amino acids produce subtle alterations in the barrier properties of the sacs, as evidenced by increased tetraethylammonium bromide-14C diffusion.
利用大鼠和仓鼠的外翻肠囊，在体外对DL-色氨酸及其1-甲基吲哚（色氨酸-1-Me）和苯并[b]噻吩（色氨酸-S）类似物的肠道转运进行了比较研究。色氨酸和色氨酸-S均通过肠道进行主动转运，而色氨酸-1-Me则不进行主动转运。色氨酸的主动转运受到色氨酸-S的竞争性抑制，表明存在相似的载体，而色氨酸-1-Me不是色氨酸转运的抑制剂，表明其与载体的相互作用很小或不存在。色氨酸和色氨酸-S的转运在浓度为10 mM时受到抑制，并且所有三种氨基酸都会使肠囊的屏障特性发生细微变化，这通过溴化四乙铵-14C扩散增加得到证明。
