Leal M A, Aller P, Mas A, Carranza M C, Calle C
Departamento de Bioquímica y Biología Molecular, Facultad de Medicina, Universidad Complutense, Madrid, Spain.
Endocr J. 1994 Dec;41(6):737-41. doi: 10.1507/endocrj.41.737.
The relative concentrations of total insulin receptor (IR) mRNA were measured in the epididymal adipose tissue and liver of intact untreated rats, dexamethasone-treated rats, adrenalectomized rats and adrenalectomized rats treated with dexamethasone, using RNA blot assays and a specific IR cDNA probe. Northern blot assays revealed two IR mRNA species of approximately 9.5 and 7.5 kb, in both tissues. Dot-Blot assays followed by densitometry indicated that dexamethasone induced an approximately three-fold increase in IR mRNA in liver, but not in epididymal adipose tissue. By contrast, neither adrenalectomy alone nor the combination of adrenalectomy plus dexamethasone treatment altered the IR mRNA concentrations in liver nor in adipose tissue, which indicates that adrenalectomy was able to prevent the stimulation of IR gene expression caused by dexamethasone in rat liver. These results provide evidence for an "in vivo" tissue-specific regulation of IR gene expression, at the mRNA level, in rats under experimental conditions of an excess or insufficiency of glucocorticoids.
使用RNA印迹分析法和特异性胰岛素受体（IR）cDNA探针，测定了完整未处理大鼠、地塞米松处理大鼠、肾上腺切除大鼠以及肾上腺切除后用地塞米松处理大鼠附睾脂肪组织和肝脏中总胰岛素受体（IR）mRNA的相对浓度。Northern印迹分析显示，在两种组织中均有两种大小约为9.5 kb和7.5 kb的IR mRNA。斑点印迹分析及光密度测定表明，地塞米松可使肝脏中IR mRNA增加约三倍，但对附睾脂肪组织无此作用。相比之下，单独肾上腺切除或肾上腺切除加地塞米松处理均未改变肝脏和脂肪组织中IR mRNA的浓度，这表明肾上腺切除能够防止地塞米松对大鼠肝脏IR基因表达的刺激作用。这些结果为在糖皮质激素过多或不足的实验条件下，大鼠体内IR基因表达在mRNA水平上存在组织特异性调节提供了证据。
