Yoshioka K, Murakami K, Maki S
Department of Pediatrics, Kinki University School of Medicine.
Nihon Rinsho. 1992 Dec;50(12):2931-6.
We selectively focus on two growth factors, epidermal growth factor (EGF) and insulin-like growth factor (IGF), and discuss their roles on regulation of renal function and associated diseases conditions, as well. EGF, 6 kD polypeptide, is derived by proteolysis from a large precursor (prepro EGF, 133 kD). Prepro EGF is a membrane-anchored protein and its mRNA is predominantly localized to distal tubules of mouse and rat kidneys. We immunohistochemically demonstrated the glomerular distribution of EGF and EGF-receptor in normal and nephritic human kidneys. The physiologic roles of EGF produced in the kidney are various; it is mitogenic for tubular epithelial cell, inhibits gluconeogenesis and salt and water reabsorption in the tubules, and effects on glomerular hemodynamics. Alteration of renal EGF expression is suggested in renal ischemic injury, renal hypertrophy and cystic renal disease. IGF-I, somatomedin-C, is produced in collecting duct, and glomerular cells, and exerts a variety of actions on kidney. IGF-I stimulates gluconeogenesis in renal tubules, and is mitogenic for mesangial cells. The administration of this growth factor increases glomerular filtration rate. Enhanced expression of renal IGF-I was observed in the uninephrectomized animals.
我们选择性地聚焦于两种生长因子，即表皮生长因子（EGF）和胰岛素样生长因子（IGF），并讨论它们在肾功能调节及相关疾病状态中的作用。EGF是一种6kD的多肽，由一种大的前体（前体EGF，133kD）经蛋白水解产生。前体EGF是一种膜锚定蛋白，其mRNA主要定位于小鼠和大鼠肾脏的远端小管。我们通过免疫组化法证实了EGF及其受体在正常和肾炎患者肾脏中的肾小球分布。肾脏产生的EGF具有多种生理作用；它对肾小管上皮细胞有促有丝分裂作用，抑制糖异生以及肾小管中的盐和水重吸收，并影响肾小球血流动力学。在肾脏缺血损伤、肾肥大和多囊肾病中提示肾脏EGF表达发生改变。IGF-I，即生长调节素C，在集合管和肾小球细胞中产生，并对肾脏发挥多种作用。IGF-I刺激肾小管中的糖异生，对系膜细胞有促有丝分裂作用。给予这种生长因子可增加肾小球滤过率。在单侧肾切除的动物中观察到肾脏IGF-I表达增强。
