Castro G D, Lopez A, Castro J A
Centro de Investigaciones Toxicológicas, CITEFA/CONICET, Buenos Aires, Argentina.
Arch Toxicol. 1988;62(5):355-8. doi: 10.1007/BF00293623.
The effect of several experimental conditions on methane (CH4) production from dimethylsulfoxide (DMSO) in incubation mixtures containing liver microsomes and NADPH generating systems was studied. The process was heat sensitive in part but a significant fraction was non-enzymatic in nature. CH4 formation from DMSO was not significantly modified by 2-diethylaminoethyl-2,2-diphenylvalerate. HC 1 (SKF 525A) or EDTA 1 mM and significantly enhanced under an atmosphere of (CO 80% + O2 20%) rather than under air. A marked increase in CH4 production was observed when paraquat (PQ) was included in incubation mixtures but not when nifurtimox (Nfx) was added. Results support the hypothesis of hydroxyl free radical (.OH) formation during PQ biotransformation but cast doubts about its production for the case of Nfx. The low temperature gas chromatographic separation of d3-CH4 from CH4 described opens the future possibility for detecting trace formation of .OH in vivo, without interference from fecal CH4 formation by administering d6-DMSO to animals and collecting exhaled gases produced, in chambers containing the entire animal.
研究了几种实验条件对含有肝微粒体和NADPH生成系统的孵育混合物中二甲基亚砜（DMSO）产生甲烷（CH4）的影响。该过程部分对热敏感，但很大一部分本质上是非酶促的。2-二乙氨基乙基-2,2-二苯基戊酸酯、HC 1（SKF 525A）或1 mM乙二胺四乙酸（EDTA）对DMSO生成CH4的过程没有显著影响，而在（80% CO + 20% O2）气氛下而非空气中，CH4生成显著增强。当在孵育混合物中加入百草枯（PQ）时，观察到CH4产量显著增加，但加入硝呋替莫（Nfx）时则没有。结果支持了PQ生物转化过程中形成羟基自由基（·OH）的假说，但对Nfx情况下羟基自由基的产生存在疑问。所描述的从CH4中低温气相色谱分离d3-CH4，为通过给动物施用d6-DMSO并在包含整个动物的舱室中收集产生的呼出气体，在不受到粪便CH4形成干扰的情况下检测体内·OH的微量形成开辟了未来可能性。
