Kono S, Kuzuya H, Okamoto M, Nishimura H, Kosaki A, Kakehi T, Okamoto M, Inoue G, Maeda I, Imura H
Department of Medicine, Kyoto University School of Medicine, Japan.
Am J Physiol. 1990 Jul;259(1 Pt 1):E27-35. doi: 10.1152/ajpendo.1990.259.1.E27.
To see if insulin receptor kinase activity alters with aging, the activity of wheat germ agglutinin-purified receptor preparations from liver and skeletal muscle was compared in 2-, 4-, 10-, and 20-mo-old rats. Basal and insulin-stimulated autophosphorylation of liver insulin receptor and its kinase activities toward histone 2b and poly(Glu4Tyr1) did not alter with aging. On the other hand, the muscle insulin receptor showed different results. Insulin-stimulated increases of autophosphorylation and the kinase activity toward histone 2b above basal were comparable in the four groups. However, insulin-stimulated phosphorylation of poly(Glu4Tyr1) was decreased in 20-mo-old rats compared with 10- and 4-mo-old rats. These results indicate that insulin receptor kinase activity could vary under certain conditions, depending on the substrate used to measure the activity. It is concluded that insulin receptor kinase activity does not change markedly during the process of aging, although subtle changes seem to exist.
为了探究胰岛素受体激酶活性是否随衰老而改变，对2月龄、4月龄、10月龄和20月龄大鼠肝脏和骨骼肌中麦胚凝集素纯化的受体制剂的活性进行了比较。肝脏胰岛素受体的基础和胰岛素刺激的自磷酸化及其对组蛋白2b和聚（Glu4Tyr1）的激酶活性不随衰老而改变。另一方面，肌肉胰岛素受体呈现出不同的结果。胰岛素刺激的自磷酸化增加以及对组蛋白2b的激酶活性在基础水平之上，在四组中相当。然而，与10月龄和4月龄大鼠相比，20月龄大鼠中胰岛素刺激的聚（Glu4Tyr1）磷酸化减少。这些结果表明，胰岛素受体激酶活性在某些条件下可能会有所不同，这取决于用于测量活性的底物。得出的结论是，尽管似乎存在细微变化，但胰岛素受体激酶活性在衰老过程中不会显著改变。
