Tang M J, Lin Y J, Huang J J
Department of Physiology, National Cheng Kung University Medical College, Tainan, Taiwan, R.O.C.
Life Sci. 1995;57(16):1477-85. doi: 10.1016/0024-3205(95)02121-x.
Attempts were made to elucidate whether thyroid hormone upregulates renal pro-epidermal growth factor (pro-EGF) gene expression, biosynthesis and release in adult rats which were rendered hypothyroid. Predominantly pro-EGF was detected in renal cortex, whereas pro-EGF and its degraded species were found in urine. We demonstrated that T3 increased pro-EGF levels in renal cortex to 2.2 +/- 0.17, 2.37 +/- 0.19, 2.73 +/- 0.25, and 3.10 +/- 0.45 fold within day 1, 2, 4 and 8, respectively following treatment. Immunoreactive EGF, assessed by immunohistochemical methods, was confined in the distal convoluted tubule and thick ascending limb of Henle. T3 markedly enhanced the density of irEGF in these nephrons. T3 augmented the concentration of urinary irEGF to 2.1, 2.2, 2.8 and 3.6 fold within day 1, 2, 4 and 8 and the abundance of urine pro-EGF to 2.53 +/- 1.39, 3.8 +/- 0.70, 3.59 +/- 1.48 fold within day 1, 2, 4, respectively. Moreover, we employed reverse transcriptase/polymerase chain reaction method to analyze relative abundance of pro-EGF mRNA in kidneys of various thyroid states and found T3 markedly increased pro-EGF mRNA levels after treatment of 1, 2 and 4 days. These results indicated that thyroid hormone augmented the gene expression, biosynthesis and excretion of pro-EGF in adult rat kidney.
研究人员试图阐明甲状腺激素是否会上调成年大鼠肾脏中前表皮生长因子（pro-EGF）的基因表达、生物合成及释放，这些成年大鼠已处于甲状腺功能减退状态。主要在肾皮质中检测到pro-EGF，而在尿液中发现了pro-EGF及其降解产物。我们证明，在治疗后的第1天、第2天、第4天和第8天，T3分别将肾皮质中的pro-EGF水平提高到2.2±0.17、2.37±0.19、2.73±0.25和3.10±0.45倍。通过免疫组织化学方法评估的免疫反应性EGF局限于远曲小管和亨氏袢的厚升支。T3显著增强了这些肾单位中irEGF的密度。T3在第1天、第2天、第4天和第8天将尿irEGF的浓度分别提高到2.1、2.2、2.8和3.6倍，在第1天、第2天和第4天分别将尿pro-EGF的丰度提高到2.53±1.39、3.8±0.70、3.59±1.48倍。此外，我们采用逆转录酶/聚合酶链反应方法分析不同甲状腺状态的大鼠肾脏中pro-EGF mRNA的相对丰度，发现T3在治疗1天、2天和4天后显著提高了pro-EGF mRNA水平。这些结果表明，甲状腺激素增强了成年大鼠肾脏中pro-EGF的基因表达、生物合成和排泄。
