Martínez-Salgado Carlos, Eleno Nélida, Tavares Paula, Rodríguez-Barbero Alicia, García-Criado Javier, Bolaños Juan P, López-Novoa José M
Departamento de Fisiología y Farmacología and Instituto Reina Sofía de Investigación Nefrológica, Universidad de Salamanca, Salamanca, Spain.
Kidney Int. 2002 Nov;62(5):1682-92. doi: 10.1046/j.1523-1755.2002.00635.x.
Reactive oxygen species (ROS) have been shown to be involved in the reduction of glomerular filtration rate observed after gentamicin (Genta) treatment in vivo, a phenomenon directly related with mesangial cell (MC) contraction. Our previous study reported that Genta induces concentration-dependent MC contraction and proliferation in vitro.
To study the possible mediation of ROS in the effect of Genta, ROS production was measured in primary cultures of rat MC stimulated with Genta (10-5 mol/L). In addition, the MC response to Genta in the presence of the ROS scavengers superoxide dismutase (SOD) and catalase (CAT) was studied. MC activation and O2- production were studied in the presence of an inhibitor of the NADP(H) oxidase, diphenylene iodinium (DPI), and in the presence of L-NAME, an inhibitor of nitric oxide synthases (NOS). Finally, the effects of Genta on SOD activity and mRNA expression were examined.
Genta (10-5 mol/L) induced an increase in O2- production and SOD activity that was neither accompanied by an elevation in cytosolic Cu/Zn-SOD mRNA expression nor by H2O2 accumulation. Genta induced MC contraction and proliferation that were inhibited by SOD plus CAT. Both the extracellular and intracellular ROS donor systems, xantine+xantine oxidase (X+XO) and dimethoxinaphtoquinone (DMNQ), respectively, also stimulated MC contraction and proliferation. Genta-induced MC activation and O2- production were inhibited by DPI. Genta-induced O2- production was inhibited by L-NAME. Furthermore, Genta did not induce detectable changes in membrane fluidity and lipid peroxidation.
These results strongly suggest that an oxidative-mediated pathway exists in Genta-induced MC activation. A portion of the production of O2- may be due to NADP(H) oxidase and NOS activation. The amount of ROS produced, rather than having a toxic effect, might play a role as a mediator of Genta-induced MC activation
活性氧（ROS）已被证明参与体内庆大霉素（Genta）治疗后观察到的肾小球滤过率降低，这一现象与系膜细胞（MC）收缩直接相关。我们之前的研究报道，Genta在体外可诱导浓度依赖性的MC收缩和增殖。
为研究ROS在Genta作用中的可能介导作用，在经Genta（10 - 5 mol/L）刺激的大鼠MC原代培养物中测量ROS生成。此外，研究了在存在ROS清除剂超氧化物歧化酶（SOD）和过氧化氢酶（CAT）的情况下MC对Genta的反应。在存在NADP（H）氧化酶抑制剂二苯碘鎓（DPI）以及一氧化氮合酶（NOS）抑制剂L - NAME的情况下研究MC活化和O2 - 生成。最后，检测Genta对SOD活性和mRNA表达的影响。
Genta（10 - 5 mol/L）诱导O2 - 生成和SOD活性增加，这既未伴随着胞质Cu/Zn - SOD mRNA表达升高，也未伴随着H2O2积累。Genta诱导MC收缩和增殖，而SOD加CAT可抑制这种作用。细胞外和细胞内ROS供体系统，即黄嘌呤 + 黄嘌呤氧化酶（X + XO）和二甲氧基萘醌（DMNQ），分别也刺激MC收缩和增殖。DPI可抑制Genta诱导的MC活化和O2 - 生成。L - NAME可抑制Genta诱导的O2 - 生成。此外，Genta未诱导可检测到的膜流动性和脂质过氧化变化。
这些结果强烈表明，在Genta诱导的MC活化中存在氧化介导途径。一部分O2 - 的产生可能归因于NADP（H）氧化酶和NOS活化。所产生的ROS量可能作为Genta诱导的MC活化的介质发挥作用，而不是具有毒性作用。
