Abstract
The mechanism of the action of sodium glycocholate (SGC), which resulted in disappearance of the inhibitory effect of sodium laurylsulfate (SLS) on the absorption of benzoylthiamine disulfide (BTDS) from rat intestine, was investigated. It was observed that membrane altering action of SGC did not contribute to the antagonistic effect of SGC against SLS, as determined by circulation experiments with BTDS after precirculation with or without SGC in the presence or absence of SLS through rat small intestine. However, studies as to the physico-chemical behaviour of BTDS such as micellar partitioning in the solution of SLS, SGC and their mixture revealed that the effect of SGC on the BTDS absorption in the presence of SLS was due to the formation of the mixed micelles, which resulted in an increase in the amount of BTDS out of the micelles. In contrast of SLS, polysorbate 80 did not show any apparent changes in the characteristic of the micelles in the presence of SGC. This finding was quite agreeable with the in situ absorption experiment of BTDS.
