Hori R, Hirai M, Katsura T, Takano M, Yasuhara M, Kaneko S, Satoh M
Department of Pharmacy, Kyoto University Hospital, Faculty of Medicine, Japan.
Biochem J. 1992 Apr 15;283 ( Pt 2)(Pt 2):409-11. doi: 10.1042/bj2830409.
The expression of the organic cation transport system of rat renal proximal tubules has been studied in Xenopus laevis oocytes injected with poly(A)+ RNA from the rat renal cortex. The effectiveness of the technique was confirmed by examining expression of the Na+/D-glucose co-transporter. Compared with water-injected and non-injected oocytes, the injection of total poly(A)+ RNA resulted in about a 3-fold increase in tetraethylammonium (TEA) uptake activity. TEA uptake by poly(A)(+)-RNA-injected oocytes was time-dependent and was inhibited by cimetidine and HgCl2, but not by p-aminohippurate. After size-fractionation on a sucrose density gradient, a 1.4-2.4 kb poly(A)+ RNA fragment was identified that expressed the organic cation transport system in oocytes. These results demonstrate that the renal organic cation transporter was expressed in oocytes and that this expression system can provide an effective assay procedure for cloning of the organic cation transporter.
通过向非洲爪蟾卵母细胞注射来自大鼠肾皮质的聚腺苷酸（poly(A)）+RNA，研究了大鼠肾近端小管有机阳离子转运系统的表达。通过检测钠/葡萄糖共转运体的表达来证实该技术的有效性。与注射水和未注射的卵母细胞相比，注射总poly(A)+RNA使四乙铵（TEA）摄取活性增加了约3倍。注射poly(A)+RNA的卵母细胞对TEA的摄取具有时间依赖性，并受到西咪替丁和氯化汞的抑制，但不受对氨基马尿酸的抑制。在蔗糖密度梯度上进行大小分级后，鉴定出一个1.4 - 2.4 kb的poly(A)+RNA片段，其在卵母细胞中表达有机阳离子转运系统。这些结果表明，肾有机阳离子转运体在卵母细胞中表达，并且该表达系统可为有机阳离子转运体的克隆提供有效的检测方法。
