钾氯共转运体在大鼠内分泌胰腺α细胞中的表达
Expression of K+-Cl- cotransporters in the alpha-cells of rat endocrine pancreas.
作者信息
Davies Sarah L, Roussa Eleni, Le Rouzic Philippe, Thévenod Frank, Alper Seth L, Best Len, Brown Peter D
机构信息
School of Biological Sciences and Department of Medicine, University of Manchester, G.38 Stopford Building, Manchester M13 9PT, UK.
出版信息
Biochim Biophys Acta. 2004 Nov 17;1667(1):7-14. doi: 10.1016/j.bbamem.2004.08.005.
The expression of K+-Cl- cotransporters (KCC) was examined in pancreatic islet cells. mRNA for KCC1, KCC3a, KCC3b and KCC4 were identified by RT-PCR in islets isolated from rat pancreas. In immunocytochemical studies, an antibody specific for KCC1 and KCC4 revealed the expression of KCC protein in alpha-cells, but not pancreatic beta-cells nor delta-cells. A second antibody which does not discriminate among KCC isoforms identified KCC expression in both alpha-cell and beta-cells. Exposure of isolated alpha-cells to hypotonic solutions caused cell swelling was followed by a regulatory volume decrease (RVD). The RVD was blocked by 10 microM [dihydroindenyl-oxy] alkanoic acid (DIOA; a KCC inhibitor). DIOA was without effect on the RVD in beta-cells. NEM (0.2 mM), a KCC activator, caused a significant decrease of alpha-cell volume, which was completely inhibited by DIOA. By contrast, NEM had no effects on beta-cell volume. In conclusion, KCCs are expressed in pancreatic alpha-cells and beta-cells. However, they make a significant contribution to volume homeostasis only in alpha-cells.
研究了钾氯共转运体（KCC）在胰岛细胞中的表达。通过逆转录聚合酶链反应（RT-PCR）在从大鼠胰腺分离的胰岛中鉴定出了KCC1、KCC3a、KCC3b和KCC4的信使核糖核酸（mRNA）。在免疫细胞化学研究中，一种针对KCC1和KCC4的特异性抗体显示KCC蛋白在α细胞中有表达，但在胰腺β细胞和δ细胞中未表达。一种不能区分KCC亚型的二抗在α细胞和β细胞中均鉴定出了KCC的表达。将分离的α细胞暴露于低渗溶液中会导致细胞肿胀，随后出现调节性容积减小（RVD）。RVD被10微摩尔/升的[二氢茚基-氧基]链烷酸（DIOA；一种KCC抑制剂）阻断。DIOA对β细胞的RVD没有影响。KCC激活剂N-乙基马来酰亚胺（NEM，0.2毫摩尔/升）导致α细胞体积显著减小，这被DIOA完全抑制。相比之下，NEM对β细胞体积没有影响。总之，KCC在胰腺α细胞和β细胞中均有表达。然而，它们仅对α细胞的容积稳态有显著贡献。
Zotero 插件