Mulroney S E, Haramati A, Roberts C T, LeRoith D
Department of Physiology and Biophysics, Georgetown University School of Medicine, Washington, DC.
Endocrinology. 1991 May;128(5):2660-2. doi: 10.1210/endo-128-5-2660.
The increase in IGF-1 gene expression following unilateral nephrectomy (UNX) in adult rats is controversial. In this study we have examined whether developmental differences exist in the effect of UNX on IGF-1 gene expression. Immature (23 days) and adult (4 months) Wistar rats underwent a sham operation or left UNX, and were sacrificed 24 or 48 hrs later. IGF-1 mRNA levels were determined in left (control) and right (compensated) kidneys using solution hybridization/RNase protection assays. By 48 hrs post-UNX, remnant kidneys had grown 20 +/- 1% in adult rats (P less than 0.05), and 69 +/- 5% in immature rats (P less than 0.05). IGF-1 mRNA levels were not increased in the adult compensated kidneys at either 24 or 48 hrs post-UNX. In contrast, kidneys from immature rats 24 and 48 hrs post-UNX had an average 4-fold increase (P less than 0.05) in exon 1 IGF-1 mRNA levels, and an average 3-fold increase (P less than 0.05) in exon 2 mRNA levels. Thus, these findings suggest that there is an age-dependent difference in the effects of UnX on IGF-1 gene expression, and provide the first evidence that IGF-1 gene expression increases following unilateral nephrectomy in immature rats.
成年大鼠单侧肾切除术后胰岛素样生长因子-1（IGF-1）基因表达增加这一现象存在争议。在本研究中，我们检测了单侧肾切除对IGF-1基因表达的影响是否存在发育差异。对未成熟（23日龄）和成年（4月龄）的Wistar大鼠进行假手术或左侧单侧肾切除术，并在术后24或48小时处死。使用溶液杂交/核糖核酸酶保护分析法测定左肾（对照）和右肾（代偿）中的IGF-1信使核糖核酸（mRNA）水平。单侧肾切除术后48小时，成年大鼠的残余肾脏增大了20±1%（P<0.05），未成熟大鼠的残余肾脏增大了69±5%（P<0.05）。单侧肾切除术后24或48小时，成年代偿肾脏中的IGF-1 mRNA水平未升高。相比之下，单侧肾切除术后24和48小时，未成熟大鼠肾脏的外显子1的IGF-1 mRNA水平平均升高了4倍（P<0.05），外显子2的mRNA水平平均升高了3倍（P<0.05）。因此，这些发现表明，单侧肾切除对IGF-1基因表达的影响存在年龄依赖性差异，并首次证明未成熟大鼠单侧肾切除术后IGF-1基因表达增加。
