Generation of oxygen free radicals during the metabolism of cyclosporine A: a cause-effect relationship with metabolism inhibition.
Generation of oxygen free radicals during the metabolism of cyclosporine A: a cause-effect relationship with metabolism inhibition.
复制标题
环孢素A代谢过程中氧自由基的产生：与代谢抑制的因果关系。
DOI：
10.1007/bf01076094
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发表时间：
1993
影响因子：
4.3
通讯作者：
Strobel,HW
中科院分区：
文献类型：
--
作者：
Serino,F;Grevel,J;Napoli,KL;Kahan,BD;Strobel,HW
更好地了解环孢素 A (CsA) 代谢过程中的脂质过氧化机制可能有助于解释这种免疫抑制药物对各种器官的毒性。我们的体外实验使用从苯巴比妥诱导的雄性大鼠肝脏制备的微粒体。培养液（总体积 1ml）还含有 NADPH 再生系统和溶解在乙醇中的底物（即 CsA、四氯化碳或氨基比林）。通过硫代巴比妥酸测定检测到的丙二醛 (MDA) 的存在推断出脂质过氧化。通过液相色谱监测 CsA 羟基化代谢物（AM9 和 AM1）的形成。通过测量 CsA、四氯化碳和氨基比林浓度增加引起的 MDA 和甲醛产生，证实了微粒体孵育的活性。羟基化代谢物的出现与 MDA 的产生无关。氨基比林可以抑制CsA产生MDA，但CsA不能减少氨基比林生成甲醛。红霉素是 CsA 在细胞色素 P450 上结合位点的竞争者，可减少 CsA 产生的 MDA，并且 CsA 抑制红霉素产生的甲醛。与 SKF 525A、酮康唑、超氧化物歧化酶、过氧化氢酶、α-生育酚和还原型谷胱甘肽的相互作用研究证实了细胞色素 P450 的作用以及活性氧物质作为微粒体过氧化来源的存在，这反过来可以解释 CsA 对细胞色素 P450 本身的抑制作用。
A better understanding of the mechanism of lipid peroxidation during the metabolism of cyclosporine A (CsA) might help explain the toxicities of this immunosuppressive drug on various organs. Ourin vitrowork used microsomes prepared from livers of phenobarbital-induced male rats. The incubations (total volume 1ml) also contained a NADPH regenerating system and substrate (i.e., CsA, carbon tetrachloride, or aminopyrine) dissolved in ethanol. Lipid peroxidation was inferred from the presence of malondialdehyde (MDA) which was detected by the thiobarbituric acid assay. The formation of CsA hydroxylated metabolites (AM9 and AM1) was monitored by liquid chromatography. The activity of the microsomal incubation was confirmed by measurements of MDA and formaldehyde production caused by increasing concentrations of CsA, carbon tetrachloride, and aminopyrine. The occurrence of hydroxylated metabolites was not coupled to the production of MDA. Aminopyrine could inhibit MDA production by CsA, but CsA could not reduce the formation of formaldehyde by aminopyrine. Erythromycin, a competitor for the binding site of CsA on cytochrome P450, reduced MDA production by CsA, and CsA inhibited formaldehyde production by erythromycin. Interaction studies with SKF 525A, ketoconazole, superoxide dismutase, catalase, α-tocopherol, and reduced glutathione confirmed the role of cytochrome P450 and the presence of activated oxygen species as a source of microsomal peroxidation which in return may explain the inhibitory effect of CsA on cytochrome P450 itself.