Zhou Ming, He Hui-Jing, Suzuki Ryoji, Liu Ke-Xiang, Tanaka Osamu, Sekiguchi Masaki, Itoh Hideaki, Kawahara Katsumasa, Abe Hiroshi
Department of Anatomy, Akita University School of Medicine, 1-1-1 Hondo, Akita 010-8543, Japan.
J Histochem Cytochem. 2007 Aug;55(8):795-804. doi: 10.1369/jhc.6A7104.2007. Epub 2007 Apr 16.
To understand the possible functions and subcellular localizations of sulfonylurea receptors (SURs) in cardiac muscle, polyclonal anti-SUR2A and anti-SUR2B antisera were raised. Immunoblots revealed both SUR2A and SUR2B expression in mitochondrial fractions of rat heart and other cellular fractions such as microsomes and cell membranes. Immunostaining detected ubiquitous expression of both SUR2A and SUR2B in rat heart in the atria, ventricles, interatrial and interventricular septa, and smooth muscles and endothelia of the coronary arteries. Electron microscopy revealed SUR2A immunoreactivity in the cell membrane, endoplasmic reticulum (ER), and mitochondria. SUR2B immunoreactivity was mainly localized in the mitochondria as well as in the ER and cell membrane. Thus, SUR2A and SUR2B are not only the regulatory subunits of sarcolemmal K(ATP) channels but may also function as regulatory subunits in mitochondrial K(ATP) channels and play important roles in cardioprotection.
为了解磺脲类受体（SURs）在心肌中的可能功能和亚细胞定位，制备了多克隆抗SUR2A和抗SUR2B抗血清。免疫印迹显示大鼠心脏线粒体部分以及其他细胞部分（如微粒体和细胞膜）中均有SUR2A和SUR2B表达。免疫染色检测到SUR2A和SUR2B在大鼠心脏的心房、心室、房间隔和室间隔以及冠状动脉的平滑肌和内皮中普遍表达。电子显微镜显示SUR2A免疫反应性存在于细胞膜、内质网（ER）和线粒体中。SUR2B免疫反应性主要定位于线粒体以及ER和细胞膜中。因此，SUR2A和SUR2B不仅是肌膜K（ATP）通道的调节亚基，还可能作为线粒体K（ATP）通道的调节亚基，并在心脏保护中发挥重要作用。
