INSULIN-II GENE-EXPRESSION IN RAT CENTRAL-NERVOUS-SYSTEM
INSULIN-II GENE-EXPRESSION IN RAT CENTRAL-NERVOUS-SYSTEM
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DOI：
10.1016/0167-0115(93)90335-6
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发表时间：
1993-10-20
影响因子：
--
通讯作者：
GIDDINGS, SJ
中科院分区：
文献类型：
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作者：
DEVASKAR, SU;SINGH, BS;GIDDINGS, SJ
关于胰岛素在中枢神经系统中的起源仍然存在争议。虽然已经有令人信服的证据表明，在体外神经元胰岛素mRNA的存在，传统的检测方法已无法检测到相同的全脑制剂。在这里，我们采用RNA酶保护和敏感的逆转录-聚合酶链反应（RT-PCR）试验，试图检测胰岛素I和II的mRNA在大鼠大脑中获得不同的发展阶段。RNA酶保护试验未检测到胎儿（妊娠13 - 21天）或成人大脑中的胰岛素I或胰岛素II转录物。RT-PCR，而检测到少量的胰岛素I转录在其他胰腺外组织，如大鼠卵黄囊和胎肝先前显示表达胰岛素II，未能检测到胰岛素I在大脑中的任何年龄检查。RT-PCR检测到胰岛素Ⅱ mRNA在胎鼠、新生鼠和成年大鼠脑中的表达，与卵黄囊、胎鼠和成年大鼠肝脏中的表达相同。我们的结论是，虽然重复的胰岛素I基因不表达，祖先胰岛素II基因在胎儿，新生儿和成年大鼠的大脑中表达。我们的观察结果支持的概念，从头脑胰岛素II的合成超过前胰腺阶段的胚胎发育。
Controversy persists concerning the origin of insulin in the central nervous system. While there has been convincing evidence in vitro to demonstrate the presence of neuronal insulin mRNA, conventional assays have failed to detect the same in whole brain preparations. Here we employed RNAse-protection and sensitive reverse transcription-polymerase chain reaction (RT-PCR) assays in attempts to detect insulin I and II mRNAs in rat brains obtained from different developmental stages. The RNAse-protection assay did not detect insulin I or insulin II transcripts in fetal (13 to 21 day gestation) or adult brains. RT-PCR, while detecting low amounts of insulin I transcripts in other extrapancreatic tissues such as the rat yolk sac and fetal liver previously shown to express insulin II, failed to detect insulin I in brain at any age examined. Insulin II mRNA was detected by RT-PCR in fetal, neonatal and adult rat brains, just as in yolk sac, fetal and adult livers. We conclude that while the duplicated insulin I gene is not expressed, the ancestral insulin II gene is expressed in fetal, neonatal and adult rat brains. Our observations support the concept of de novo brain insulin II synthesis beyond the pre-pancreatic stage of embryonic development.