丙吡胺对映体与血浆蛋白位点的相互作用。

Interaction of disopyramide enantiomers for sites on plasma protein.

作者信息

Lima J J

机构信息

Division of Pharmacy Practice, College of Pharmacy, Ohio State University, Columbus.

出版信息

Life Sci. 1987 Dec 28;41(26):2807-13. doi: 10.1016/0024-3205(87)90426-7.

DOI:10.1016/0024-3205(87)90426-7

PMID:3695808

Abstract

The binding of disopyramide enantiomers to donor plasma to which had been added human alpha-1 acid glycoprotein (AAG) was characterized alone and in the presence of the opposite enantiomer. At pre-dialysis concentrations of 10(-5) M, S(+)-disopyramide increased the percent of R(-)-disopyramide free (unbound) 2.6-fold from 11 to 30%. At similar pre-dialysis concentrations, R(-)-disopyramide increased the percent of S(+)-disopyramide free 2-fold from 4.1 to 9.0%. Differences in the binding of one enantiomer due to the presence of the other were due to apparent changes in association constant; no changes in capacity to bind the enantiomers were observed. It is concluded that the enantiomers of disopyramide compete with each other for one site on AAG.

摘要

研究了丙吡胺对映体与添加了人α-1酸性糖蛋白（AAG）的供体血浆的结合情况，分别在单独存在及有对映体的情况下进行了表征。在透析前浓度为10⁻⁵ M时，S(+)-丙吡胺使R(-)-丙吡胺的游离（未结合）百分比从11%增加到30%，增幅为2.6倍。在类似的透析前浓度下，R(-)-丙吡胺使S(+)-丙吡胺的游离百分比从4.1%增加到9.0%，增幅为2倍。一种对映体的结合因另一种对映体的存在而产生差异，这是由于缔合常数的明显变化；未观察到对映体结合能力的变化。得出结论，丙吡胺的对映体在AAG的一个位点上相互竞争。