Ozaki K, Takada N, Tsujimoto K, Tsuji N, Kawamura T, Muso E, Ohta M, Itoh N
Department of Genetic Biochemistry, Kyoto University Faculty of Pharmaceutical Sciences, Japan.
Kidney Int. 1997 Sep;52(3):694-8. doi: 10.1038/ki.1997.384.
Insulin receptor-related receptor (IRR), a member of the insulin receptor family, is most abundantly expressed in the kidney. However, its endogenous ligand and physiological roles are still unknown. To elucidate the physiological role of IRR, an orphan receptor, in the kidney, we examined the localization of IRR mRNA and its immunoreactivity in the rat kidney by in situ hybridization and immunohistochemistry, respectively. IRR mRNA was found to be exclusively localized in the cortical collecting duct. The localization of IRR immunoreactivity was consistent with that of IRR mRNA. Furthermore, IRR immunoreactivity was found to be localized on the basolateral plasma membrane of the epithelial cells that were a minor cell subpopulation (20 to 30%) of the duct. The present findings indicated that IRR in the kidney was exclusively localized on the basolateral plasma membrane of type B intercalated cells of the cortical collecting duct.
胰岛素受体相关受体（IRR）是胰岛素受体家族的成员之一，在肾脏中表达最为丰富。然而，其内源性配体和生理作用仍不清楚。为了阐明孤儿受体IRR在肾脏中的生理作用，我们分别通过原位杂交和免疫组织化学检测了IRR mRNA在大鼠肾脏中的定位及其免疫反应性。发现IRR mRNA仅定位在皮质集合管。IRR免疫反应性的定位与IRR mRNA的定位一致。此外，发现IRR免疫反应性定位在导管中占少数细胞亚群（20%至30%）的上皮细胞的基底外侧质膜上。目前的研究结果表明，肾脏中的IRR仅定位在皮质集合管B型闰细胞的基底外侧质膜上。
