THE ROLE OF AGEs FORMATION OF KIDNEY IN THE PATHOGENESIS OF DIABETIC NEPHROPATHY

为了探讨肾脏AGEs形成在糖尿病肾病发病机制中的作用，我使用抗交叉线（XL）抗体进行了体内和体外研究。XL是一种主要的糖基化终产物（AGEs）荧光蛋白（Ex/Em 379/463 nm），在体外由赖氨酸和D-葡萄糖反应生成。(1)AGEs形成和NO生成在糖尿病肾病发病中的作用：SZ糖尿病大鼠在注射SZ后4周内尿白蛋白排泄量和肾脏XL形成显著升高，并持续升高至研究结束。SZ注射后2周尿NO_3（U-NO_3）和c-GMP排泄量随GFR升高而增加，给予NO抑制剂N-硝基精氨酸（NNA）可抑制SZ糖尿病大鼠GFR、RBF和U-NO_3的升高。此外，给予NNA还抑制了皮质肾组织中抗C-NOS抗体的染色。提示肾脏AGEs的形成和NO的产生在糖尿病肾病的发病中起重要作用。(2)XL体内代谢产物的测定：我们建立了竞争ELISA法测定生物样品中的XL。糖尿病患者血清、红细胞膜及组织蛋白中XL含量均显著高于非糖尿病患者。生物标本中XL的测定可作为糖尿病并发症发生发展的一个指标。

To investigate the role of renal AGEs formation in the pathogenesis of diabetic nephropathy, I performed in vivo and in viro study using anti-crossline (XL) antibodies. XL is a isolated major in fluoresent advanced glycation end products (AGEs) (Ex/Em 379/463nm) resulting the reaction mixture ofepsilon-one lysine with D-glucose in vitro.(1) The role of AGEs formation and NO production in the pathogenesis of diabetic nephropathy : Urinary albumin excretion and renal XL formation of SZ diabetic rats were elevated significantly within 4 wks of SZ injection and continued to rise until the end of study. Urinary NO_3 (U-NO_3) and c-GMP excretion increased at 2 wks of SZ injection with the elevation of GFR.Administration of NO inhibitor, N-nitroarginine (NNA) to SZ-diabeic rats could suppress the elevated levels of GFR,RBF and U-NO_3. Moreover, administration of NNA suppressed anti C-NOS antibody staininng in cortical renal tissues. These results suggested that renal AGEs formation and NO production play a important role in the pathogenesis of diabetic nephropathy.(2) The measurement of XL in vivo speciments : We developed the competitive ELISA system to measure XL in biological specimens. The levels of XL in there serum, red blood cell membrane and tissue proteins in diabetic subjects were siginicatlly increased compared to those in non-diabetic ones. Mesurement of XL in biological specimens may provide an index of of the develpment of diabetic complications.