Carvalho C R, Maeda L, Brenelli S L, Saad M J
Departamento de Clínica Médica, Faculdade de Ciências Médicas, Universidade Estadual de Campinas, SP, Brazil.
Biol Chem. 2000 Jan;381(1):75-8. doi: 10.1515/BC.2000.010.
We have examined the insulin-stimulated IRS-2 association with PI 3-kinase and the phosphorylation of AKT/PKB, which is functionally located downstream of the PI 3-kinase, in aged (obese) rats. The IRS-2 protein levels were similar in 2 and 20 month-old rats in both tissues, liver and muscle. There were reductions in insulin-induced IRS-2 tyrosine phosphorylation in liver and muscle, accompanied by a decrease in IRS-2/PI 3-kinase association and in AKT/PKB phosphorylation only in muscle tissue of aged rats. This regulation may be important in the altered glucose metabolism observed in aged (obese) rats.
我们研究了胰岛素刺激的IRS-2与PI 3激酶的结合以及AKT/PKB的磷酸化情况，AKT/PKB在功能上位于PI 3激酶下游，研究对象为老年（肥胖）大鼠。在肝脏和肌肉这两种组织中，2月龄和20月龄大鼠的IRS-2蛋白水平相似。老年大鼠肝脏和肌肉中胰岛素诱导的IRS-2酪氨酸磷酸化减少，同时仅在老年大鼠肌肉组织中，IRS-2/PI 3激酶结合以及AKT/PKB磷酸化减少。这种调节可能在老年（肥胖）大鼠中观察到的葡萄糖代谢改变中起重要作用。
