Uyemura S A, Santos A C, Mingatto F E, Jordani M C, Curti C
Department of Clinical, Toxicological, and Bromatological Analysis, School of Pharmaceutical Sciences, University of São Paulo, Brazil.
Arch Biochem Biophys. 1997 Jun 15;342(2):231-5. doi: 10.1006/abbi.1997.9985.
The ability of nonsteroidal anti-inflammatory drugs (NSAIDs) to induce Ca(2+)-mediated/cyclosporin A-sensitive mitochondrial membrane permeability transition (MMPT) was evaluated by monitoring swelling of isolated rat renal cortex mitochondria in the presence of 20 microM CaCl2. Dipyrone and paracetamol did not induce MMPT, while piroxicam and acetylsalicylic acid (and its metabolite salicylate) were poor inducers. In contrast, diclofenac sodium and mefenamic acid were potent triggering agents, inducing MMPT at 2 microM, a concentration below those previously shown to uncouple and/or inhibit oxidative phosphorylation. When compared to salicylate, a classical uncoupler and inducer of MMPT, the potency of diclofenac sodium and mefenamic acid was about 50-fold greater. Swelling was completely prevented by EGTA, cyclosporin A, or MgCl2, and only partially by ADP or dithiothreitol. Under the same experimental conditions as for the swelling assays, the drugs depressed the membrane potential of mitochondria, an effect prevented by cyclosporin A and restored by EGTA. Also, the drugs did not induce membrane lipid peroxidation or changes in GSSG levels, but led to a small decrease in protein thiol content, as well as to a substantial decrease in the NADPH levels of mitochondria. Hence, membrane depolarization and pyridine nucleotide oxidation seem to be involved in MMPT induction by these NSAIDs. The potency in eliciting the process, like the uncoupling activity, seems to be influenced by the lipophilic character of the molecules.
通过监测在20微摩尔氯化钙存在下分离的大鼠肾皮质线粒体的肿胀情况，评估了非甾体抗炎药（NSAIDs）诱导钙介导/环孢素A敏感的线粒体膜通透性转换（MMPT）的能力。安乃近和对乙酰氨基酚未诱导MMPT，而吡罗昔康和乙酰水杨酸（及其代谢产物水杨酸盐）诱导能力较弱。相比之下，双氯芬酸钠和甲芬那酸是强效触发剂，在2微摩尔浓度下即可诱导MMPT，该浓度低于先前显示可解偶联和/或抑制氧化磷酸化的浓度。与经典的MMPT解偶联剂和诱导剂水杨酸盐相比，双氯芬酸钠和甲芬那酸的效力大约高50倍。乙二醇双四乙酸（EGTA）、环孢素A或氯化镁可完全阻止肿胀，而二磷酸腺苷（ADP）或二硫苏糖醇只能部分阻止。在与肿胀试验相同的实验条件下，这些药物降低了线粒体的膜电位，环孢素A可阻止这种作用，而EGTA可使其恢复。此外，这些药物未诱导膜脂质过氧化或谷胱甘肽二硫化物（GSSG）水平变化，但导致蛋白质巯基含量略有下降，以及线粒体烟酰胺腺嘌呤二核苷酸磷酸（NADPH）水平大幅下降。因此，膜去极化和吡啶核苷酸氧化似乎参与了这些NSAIDs诱导的MMPT。引发该过程的效力，如同解偶联活性一样，似乎受分子亲脂性的影响。
