Leal M A, Aller P, Calle C
Departamento de Bioquímica y Biología Molecular, Facultad de Medicina, Universidad Complutense, Madrid, Spain.
J Endocrinol Invest. 1996 Sep;19(8):530-4. doi: 10.1007/BF03349012.
The administration of 5 x 10(-6) mol/l dexamethasone transiently increased insulin receptor (IR) mRNA levels in U-937 human promonocytic cells, which reached the maximum level at 15 h of treatment. Dexamethasone treatment did not affect the IR mRNA half-life (approximately 4 h), suggesting that the increase is regulated at the transcriptional level. The stimulatory action of dexamethasone was not prevented by the simultaneous presence of the protein synthesis inhibitor cycloheximide, indicating that the induction of IR gene transcription occurs as a direct response to the action of the synthetic glucocorticoid. Finally, the A isoform (lacking exon 11) was found to be the only IR isoform present in both untreated and dexamethasone treated-U-937 cells.
5×10⁻⁶ mol/l地塞米松的给药使U - 937人原单核细胞中的胰岛素受体（IR）mRNA水平短暂升高，在处理15小时时达到最高水平。地塞米松处理不影响IR mRNA的半衰期（约4小时），提示这种增加是在转录水平受到调控。地塞米松的刺激作用不会因同时存在蛋白质合成抑制剂环己酰亚胺而受到抑制，这表明IR基因转录的诱导是对合成糖皮质激素作用的直接反应。最后，发现A亚型（缺少外显子11）是未处理和地塞米松处理的U - 937细胞中唯一存在的IR亚型。
