Nielsen D A, Welsh M, Casadaban M J, Steiner D F
J Biol Chem. 1985 Nov 5;260(25):13585-9.
To define the mechanism whereby glucose regulates islet insulin mRNA content, insulin gene transcription rates were determined in islets labeled with [3H]uridine at low (3.3) or high (17 mM) glucose. Glucose stimulated the transcription of total RNA almost 2-fold and insulin mRNA 5.6-fold. Addition of dibutyryl cAMP to islets in vitro could partially mimic the effect of glucose on insulin gene-specific transcription. In the insulin-producing RIN-5F cell line, glucose did not affect transcription, while cholera toxin acted as a secretagogue and increased total RNA and insulin gene-specific transcription as well. We conclude that glucose exerts a specific stimulatory effect on the transcription of the insulin gene(s) in normal islets and that this effect may be mediated in part by cAMP.
为了确定葡萄糖调节胰岛胰岛素mRNA含量的机制，在低（3.3）或高（17 mM）葡萄糖条件下，用[3H]尿苷标记胰岛，测定胰岛素基因转录率。葡萄糖使总RNA转录增加近2倍，胰岛素mRNA转录增加5.6倍。体外向胰岛中添加二丁酰cAMP可部分模拟葡萄糖对胰岛素基因特异性转录的作用。在产生胰岛素的RIN-5F细胞系中，葡萄糖不影响转录，而霍乱毒素作为促分泌剂，可增加总RNA和胰岛素基因特异性转录。我们得出结论，葡萄糖对正常胰岛中胰岛素基因的转录具有特异性刺激作用，且这种作用可能部分由cAMP介导。
