Pigoso A A, Uyemura S A, Santos A C, Rodrigues T, Mingatto F E, Curti C
Departamento de Física e Química, Faculdade de Ciências Farmacêuticas-USP, Ribeirão Preto S.P., Brazil.
Int J Biochem Cell Biol. 1998 Sep;30(9):961-5. doi: 10.1016/s1357-2725(98)00030-2.
In the present study we investigated the influence of several nonsteroidal anti-inflammatory drugs on calcium efflux in isolated rat renal cortex mitochondria in order to assess their potential to disrupt cell calcium homeostasis, as well as aspects of the mechanisms associated with oxidation of mitochondrial pyridine nucleotides (NAD(P)H) and with inhibition of the process by cyclosporin A (CsA). Calcium efflux was estimated with arsenazo III as an indicator and the redox state of NAD(P)H was monitored fluorimetrically at the 366/450 nm excitation/emission wavelength pair. Dipyrone, paracetamol and ibuprofen did not induce calcium efflux even at 1 mM, piroxicam and salicylate were poor inducers, while diclofenac sodium and mefenamic acid were potent inducers releasing calcium even at 20 microM and 10 microM, respectively. In the presence of 10 microM calcium, CsA had no appreciable effect while in the presence of 30 microM calcium it delayed calcium efflux. Oxidation of mitochondrial NAD(P)H, concomitant with calcium efflux and inhibited by CsA, was observed only in the presence of 30 microM calcium. The results suggest that diclofenac sodium and mefenamic acid induce calcium efflux in mitochondria through both a mechanism intrinsic to the mitochondrial membrane permeability transition and a mechanism including the electroneutral Ca2+/nH+ porter.
在本研究中，我们研究了几种非甾体抗炎药对离体大鼠肾皮质线粒体钙外流的影响，以评估它们破坏细胞钙稳态的潜力，以及与线粒体吡啶核苷酸（NAD(P)H）氧化和环孢素A（CsA）对该过程的抑制相关的机制方面。以偶氮胂III作为指示剂估计钙外流，并在366/450 nm激发/发射波长对下通过荧光法监测NAD(P)H的氧化还原状态。即使在1 mM浓度下，安乃近、对乙酰氨基酚和布洛芬也不会诱导钙外流，吡罗昔康和水杨酸盐是较弱的诱导剂，而双氯芬酸钠和甲芬那酸是强效诱导剂，分别在20 microM和10 microM时就能释放钙。在存在10 microM钙的情况下，CsA没有明显作用，而在存在30 microM钙的情况下，它会延迟钙外流。仅在存在30 microM钙的情况下，观察到线粒体NAD(P)H的氧化与钙外流同时发生并受CsA抑制。结果表明，双氯芬酸钠和甲芬那酸通过线粒体膜通透性转换固有的机制和包括电中性Ca2+/nH+转运体的机制在线粒体中诱导钙外流。
