Taylor C A, Varandani P T
Diabetologia. 1981 Nov;21(5):464-9. doi: 10.1007/BF00257787.
Glutathione-insulin transhydrogenase catalyzed the inactivation of insulin by splitting the hormone into A and B chains. We have localized this enzyme immunocytochemically by light microscopy in the pancreas, kidney and liver of both lean and obese (ob/ob) mice and similarly in normal and streptozotocin-diabetic rats. Localization was achieved by an antibody to glutathione-insulin transhydrogenase using a peroxidase-antiperoxidase technique. In comparison with tissues from control animals, positive immunostaining for glutathione-insulin transhydrogenase was increased in the obese mouse but reduced in the diabetic rat. Different tissues showed considerable variation in the amount of glutathione-insulin transhydrogenase which could be detected. In the pancreatic islets there was little or no evidence for the presence of the enzyme in peripheral cells. In the kidney, immunocytochemical staining was found only in the proximal tubules. In the liver there was a generalised distribution of the enzyme, but the greatest concentration was in the periportal region. These observations parallel the biochemical data relating to glutathione-insulin transhydrogenase, indicating that different amount of insulin degrading activity exist in different regions of tissues.
谷胱甘肽 - 胰岛素转氢酶通过将胰岛素裂解为A链和B链来催化胰岛素失活。我们已通过光学显微镜免疫细胞化学方法，在瘦小鼠和肥胖（ob/ob）小鼠的胰腺、肾脏和肝脏中，以及同样在正常大鼠和链脲佐菌素诱导的糖尿病大鼠中定位了这种酶。使用过氧化物酶 - 抗过氧化物酶技术，通过针对谷胱甘肽 - 胰岛素转氢酶的抗体实现了定位。与对照动物的组织相比，肥胖小鼠中谷胱甘肽 - 胰岛素转氢酶的阳性免疫染色增加，而糖尿病大鼠中则减少。不同组织中可检测到的谷胱甘肽 - 胰岛素转氢酶量存在相当大的差异。在胰岛中，几乎没有证据表明外周细胞中存在该酶。在肾脏中，免疫细胞化学染色仅在近端小管中发现。在肝脏中，该酶呈广泛分布，但最高浓度位于门周区域。这些观察结果与有关谷胱甘肽 - 胰岛素转氢酶的生化数据一致，表明不同组织区域存在不同量的胰岛素降解活性。
