Zinchenko V P, Goncharov N V, Teplova V V, Kasymov V A, Petrova O I, Berezhnov A V, Senchenkov E V, Mindukshev I V, Jenkins R O, Radilov A S
Tsitologiia. 2007;49(12):1023-31.
Mitochondrial aconitase has been shown to be inactivated by a spectrum of substances or critical states. Fluoroacetate (FA) is the most known toxic agent inhibiting aconitase. The biochemistry of toxic action of FA is rather well understood, though no effective therapy has been proposed for the past six decades. In order to reveal novel approaches for possible antidotes to be developed, experiments were performed with rat liver mitochondria, Ehrlich ascite tumor cells and cardiomyocytes, exposed to FA or fluorocitrate in vitro. The effect of FA developed at much higher concentrations in comparison with fluorocitrate and was dependent upon respiratory substrates in experiments with mitochondria: with pyruvate, FA induced a slow oxidation and/or leak of pyridine nucleotides and inhibition of respiration. Oxidation of pyridine nucleotides was prevented by incubation of mitochondria with cyclosporin A. Studies of the pyridine nucleotides level and calcium response generated in Ehrlich ascite tumor cells under activation with ATP also revealed a loss of pyridine nucleotides from mitochondria resulting in a shift in the balance of mitochondrial and cytosolic NAD(P)H under exposure to FA. An increase of cytosolic [Ca2+] was observed in the cell lines exposed to FA and is explained by activation of plasma membrane calcium channels; this mechanism, could have an impact on amplitude and rate of Ca2+ waves in cardiomyocytes. Highlighting the reciprocal relationship between intracellular pyridine nucleotides and calcium balance, we discuss metabolic pathway modulation in the context of probable development of an effective therapy for FA poisoning and other inhibitors of aconitase.
线粒体乌头酸酶已被证明会被一系列物质或关键状态所灭活。氟乙酸（FA）是最知名的抑制乌头酸酶的有毒物质。尽管在过去六十年里尚未提出有效的治疗方法，但FA毒性作用的生物化学过程已得到相当深入的了解。为了揭示可能开发出解毒剂的新方法，我们对大鼠肝线粒体、艾氏腹水瘤细胞和心肌细胞进行了体外暴露于FA或氟柠檬酸的实验。与氟柠檬酸相比，FA在更高浓度下产生作用，并且在使用线粒体的实验中其作用取决于呼吸底物：使用丙酮酸时，FA会诱导吡啶核苷酸的缓慢氧化和/或泄漏以及呼吸抑制。线粒体与环孢素A一起孵育可防止吡啶核苷酸的氧化。对ATP激活下艾氏腹水瘤细胞中吡啶核苷酸水平和钙反应的研究还表明，暴露于FA时线粒体中的吡啶核苷酸会流失，导致线粒体和胞质NAD(P)H平衡发生变化。在暴露于FA的细胞系中观察到胞质[Ca2+]增加，这是由质膜钙通道的激活所解释的；这种机制可能会影响心肌细胞中Ca2+波的幅度和速率。在强调细胞内吡啶核苷酸与钙平衡之间的相互关系时，我们在可能开发FA中毒及其他乌头酸酶抑制剂有效治疗方法的背景下讨论代谢途径的调节。
