High concentration of glucose inhibits glomerular endothelial eNOS through a PKC mechanism
High concentration of glucose inhibits glomerular endothelial eNOS through a PKC mechanism
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DOI：
10.1152/ajprenal.00006.2004
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发表时间：
2004-09-01
影响因子：
4.2
通讯作者：
Bohlen, HG
中科院分区：
文献类型：
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作者：
Chu, SY;Bohlen, HG
我们假设高浓度的葡萄糖可以通过蛋白激酶 C (PKC) 机制抑制肾小球内皮一氧化氮合酶 (eNOS)，正如在其他组织中发现的那样。将小鼠肾切片（150 - 200 mM）浸泡在含有 100 mM L-精氨酸的 Hanks 溶液中，并暴露于 5 或 20 - 30 mM D-葡萄糖。免疫荧光仅鉴定正常小鼠肾小球中的 eNOS。使用共聚焦显微镜和 NO 敏感微电极用 NO 敏感荧光染料（4,5-二氨基荧光素二乙酸酯）测量肾小球 NO 浓度，证实静息肾小球活跃产生 NO，而 NO 被 N-G-硝基-L-精氨酸甲酯抑制。高浓度（20 - 30 mM）D-葡萄糖在15 - 30分钟内抑制60 - 70%的NO产生；相同浓度的L-葡萄糖没有任何作用。用 100 nM ruboxistaurin 抑制 PKC-β 可防止高葡萄糖培养基中的 eNOS 抑制。用 100 nM 佛波酯激活 PKC 也抑制肾小球 NO 浓度。我们得出的结论是，在高葡萄糖浓度下，肾小球毛细血管内皮细胞中的 eNOS 受到 PKC 活性的抑制，与糖尿病动物和人类的情况相当。其结果是，在高浓度葡萄糖存在的情况下，肾小球内皮细胞中 NO 的产生迅速下降。
We hypothesized a high concentration of glucose could suppress glomerular endothelial nitric oxide synthase ( eNOS) by a protein kinase C (PKC) mechanism, as has been found in other tissues. Mouse kidney slices ( 150 - 200 mum) were bathed in Hanks' solution with 100 muM L-arginine and exposed to either 5 or 20 - 30 mM D-glucose. Immunofluorescence identified only eNOS in normal mouse glomeruli. Measurements of glomerular NO concentration with NO-sensitive fluorescent dye ( 4,5-diaminofluorescein diacetate) using confocal microscopy and NO-sensitive microelectrodes verified that resting glomeruli had active production of NO that was inhibited by N-G-nitro-L- arginine methyl ester. High-concentration ( 20 - 30 mM) D-glucose inhibited 60 - 70% of the NO production within 15 - 30 min; L-glucose at the same concentration did not have any effect. Inhibition of PKC-beta with 100 nM ruboxistaurin prevented eNOS suppression in high-glucose media. Activation of PKC with 100 nM phorbol ester also suppressed the glomerular NO concentration. We concluded that eNOS in the renal glomerular capillary endothelial cells is suppressed by activity of PKC at high-glucose concentrations comparable to those in diabetic animals and humans. The consequence is a rapid decline in the generation of NO in the glomerular endothelial cells in the presence of a high concentration of glucose.