Department of Anatomy, Akita University Graduate School of Medicine and Faculty of Medicine, 1-1-1 Hondo, Akita 010-8543, Japan.
J Histochem Cytochem. 2010 Jun;58(6):499-507. doi: 10.1369/jhc.2009.955047. Epub 2009 Nov 24.
ATP-sensitive K(+) (K(ATP)) channel subunits were investigated in rat submandibular gland (SMG). RT-PCR detected the presence of mRNA transcripts of the Kir6.1, Kir6.2, SUR2A, and SUR2B in the SMG, whereas SUR1 mRNA was barely detected. Western blot analysis provided the evidence that these four K(ATP) channel subunits are expressed in rat SMG. Immunostaining detected that these four K(ATP) channel subunits are widely distributed, with different intensities, in myoepithelial cells, epithelial cells of intercalated ducts, granular convoluted tubules, striated ducts, and excretory ducts. Immunofluorescence double staining showed that Kir6.1 and Kir6.2 colocalized with SUR2A in the myoepithelial cells, granular convoluted tubules, striated ducts, and excretory ducts. Kir6.1 and Kir6.2 also colocalized with SUR2B, mainly in the duct system, e.g., the granular convoluted tubules, striated ducts, and excretory ducts. Taken together, these results indicate that the K(ATP) channels in SMG may consist of Kir6.1, Kir6.2, SUR2A, and SUR2B, with various combinations of colocalization with each other, and may play important roles in rat SMG during salivary secretion.
ATP 敏感性钾通道（KATP）亚基在大鼠颌下腺（SMG）中进行了研究。RT-PCR 检测到 SMG 中 Kir6.1、Kir6.2、SUR2A 和 SUR2B 的 mRNA 转录本的存在，而 SUR1 mRNA 几乎检测不到。Western blot 分析提供了证据表明这四个 KATP 通道亚基在大鼠 SMG 中表达。免疫染色显示，这四个 KATP 通道亚基在肌上皮细胞、闰管上皮细胞、颗粒卷曲管、纹状管和排泄管中广泛分布，强度不同。免疫荧光双重染色显示，Kir6.1 和 Kir6.2 在肌上皮细胞、颗粒卷曲管、纹状管和排泄管中与 SUR2A 共定位。Kir6.1 和 Kir6.2 也与 SUR2B 共定位，主要在导管系统中，例如颗粒卷曲管、纹状管和排泄管。综上所述，这些结果表明，SMG 中的 KATP 通道可能由 Kir6.1、Kir6.2、SUR2A 和 SUR2B 组成，彼此之间存在各种组合的共定位，并可能在大鼠 SMG 的唾液分泌过程中发挥重要作用。
