Kim S K, Cuzzort L M, Allen E D
Research Service, V.A. Medical Center, Ann Arbor, MI 48105.
Mech Ageing Dev. 1991 May;58(2-3):151-61. doi: 10.1016/0047-6374(91)90089-i.
During aging, protein synthesis undergoes decremental changes in many organs and tissues. In the pancreas, as well as in other exocrine glands, the rate of protein synthesis declines with age. However, it is unknown whether this decline is related to intrinsic aging changes which affect the secretory cell function. In this study, we compared the ability of pancreatic acinar cells to synthesize amylase and its messenger RNA (mRNA) in response to insulin treatment of young and old rats rendered diabetic with streptozotocin (STZ). In STZ-induced diabetic rats, amylase protein and its mRNA levels were reduced drastically in the pancreas of young and old groups. Injections of these diabetic rats with insulin increased pancreatic amylase mRNA contents significantly in both young and old rats. Insulin also increased proportions of amylase protein synthesis in the pancreas of both age groups. These results indicate that the pancreatic cells remain effective during aging in their transcriptional activity for functional amylase mRNA in response to an exogenous stimulus of insulin.
在衰老过程中，许多器官和组织中的蛋白质合成都会发生递减变化。在胰腺以及其他外分泌腺中，蛋白质合成速率会随着年龄增长而下降。然而，这种下降是否与影响分泌细胞功能的内在衰老变化有关尚不清楚。在本研究中，我们比较了用链脲佐菌素（STZ）诱导患糖尿病的年轻和老年大鼠在接受胰岛素治疗后，胰腺腺泡细胞合成淀粉酶及其信使核糖核酸（mRNA）的能力。在STZ诱导的糖尿病大鼠中，年轻组和老年组胰腺中的淀粉酶蛋白及其mRNA水平均大幅降低。给这些糖尿病大鼠注射胰岛素后，年轻和老年大鼠胰腺中的淀粉酶mRNA含量均显著增加。胰岛素还增加了两个年龄组胰腺中淀粉酶蛋白质合成的比例。这些结果表明，在衰老过程中，胰腺细胞对外源胰岛素刺激产生功能性淀粉酶mRNA的转录活性仍然有效。
