Open AccessLocalization of Sulfonylurea Receptor Subunits, SUR2A and SUR2B, in Rat Heart
Author(s) -
Ming Zhou,
Huijing He,
Ryoji Suzuki,
Ke-Xiang Liu,
Osamu Tanaka,
Masaki Sekiguchi,
Hidenori Itoh,
Katsumasa Kawahara,
Hiroshi Abe
Publication year - 2007
Publication title -
journal of histochemistry and cytochemistry/the journal of histochemistry and cytochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.971
H-Index - 124
eISSN - 1551-5044
pISSN - 0022-1554
DOI - 10.1369/jhc.6a7104.2007
Subject(s) - sulfonylurea receptor , endoplasmic reticulum , mitochondrion , immunostaining , microbiology and biotechnology , chemistry , cytoplasm , subcellular localization , cell , receptor , biology , medicine , biochemistry , immunohistochemistry , protein subunit , gene
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. (J Histochem Cytochem 55: 795–804, 2007)