Molecular approaches to the pathogenesis of glomerulanephritis by vasoactive substances

肾单位段是异质性的，内皮素(ET)-1、ET-3、血管紧张素Ⅱ(AT II)、EGF和IGF-1受体沿肾单位段分布不同。我们发现血管加压素受体的两种类型(V2、V1)和血管紧张素II受体的聚合酶链式反应定位。我们还报道了ET-3mRNA和蛋白在肾单位节段的定位。近年来，生长因子和血管活性物质被报道可刺激丝裂原活化蛋白激酶(MAP-K)。在本研究中，我们用RT-PCR技术证明了MEK-K、Raf-1-K、MAPK-K、MAP-Ks(P42和P44)和S6-K的mRNA在肾单位节段中表达。我们发现MAP-K级联在每个肾单位节段都有表达。ET-1、ET-3、ATⅡ、EGF和IGF-I刺激MAP-K沿肾单位段呈异质性级联。结论：MAP-K级联在肾功能调节中起重要作用。我们还报道了C型利钠因子及其受体(GC-B)沿肾单位的存在。CNP系统可能在调节盐分、体液动态平衡和血压方面发挥重要作用。我们还分析了PDGF及其受体在IgA肾病患者肾小球中的表达。因此，我们探讨了肾小球肾炎发病机制和肾功能的新途径。

Renal nephron segments were heterogeneous, and receptors for endothelin (ET)-1, ET-3, Angiotensin II (AT II), EGF,and IGF-1 distribute differently along the nephron segments. We have revealed that the PCR localizatoin of two types (V2, V1) of vasopressin receptor, and angiotensin II receptor. We also reported that localization of mRNA and protein of ET-3 along the nephron segments. Recently, growth factors and vasoactive substances are reported to stimulate mitogen-activated protein kinase (MAP-K). In this study, we showed that mRNA of MEK-K,Raf-1-K,MAPK-K,MAP-Ks(p42 and p44), and S6-K was expressed in nephron segments using RT-PCR technique. We showed that MAP-K cascades are expressed in every nephron segment. ET-1, ET-3, AT II,EGF,and IGF-I stimulate MAP-K cascades heterogeneously along the nephron segment. We concluded that MAP-K cascades play an important role in the regulation of renal function. We also reported that the presence of C-type natriuretic factor and its receptor (GC-B) along the nephron. The CNP system may play an important roles in modulatiing the salt and body fluid homeostasis and blood pressure. We also analyzed the expression of PDGF and PDGF-receptor expression in the glomeruli of IgA nephropathy patients. Thus, we investigated the new approaches to the pathogenesis of glomerulonephritis and renal functions.