Analysis of the effects of xenobiotic free radicals on aging by using ESR microscopy technique.

虽然自由基在药物代谢产物中的存在可以从我们现代环境中的终产物分析中推断出来，但这些异源性自由基对衰老的影响还没有进行研究。在本项目中，我们使用低频体内电子自旋共振（ESR）光谱研究了几种药物产生的异源性自由基对小鼠衰老的影响。(1)我们采用ESR自旋捕获技术在体内检测形成的5，5-二甲基-1-吡咯啉-N-氧化物（DMPO）/血红蛋白巯基自由基在大鼠后，无论是肼或苯肼。用L-带ESR波谱仪观察了大鼠血红蛋白巯基自由基的六条强固定化ESR谱线。(2)诱导NO合成酶产生的一氧化氮（NO）的非侵入性检测：我们已经进行了直接，实时，在体内测量NO在小鼠中使用的水溶性金属螯合剂络合物，N-甲基-D-葡糖胺二硫代氨基甲酸盐（MGD），和Fe（II）的ESR监测在L波段微波频率。在脂多糖（LPS）处理的小鼠体内，非侵入性地获得了产物[（MGD）_2-Fe（II）-NO]的三线ESR谱。频谱显着抑制的管理，LPS注射前，苯基N-叔丁基硝酮（PBN），诱导的NO合酶的表达的抑制剂。(3)[（MGD）_2-Fe（II）-NO]在体ESR测定表明，NO主要产生于上腹部靠近肝脏的部位。在肝脏中检测到的NO复合物的浓度最大约为100 μ M。

Although the existence of free radicals in drug metabolites can be inferred from end product analysis in our modern environment, no study on the effects of these xenobiotic free radicals on aging has been carried out.In this project, we have studied the effects of xenobiotic free radicals generated from several drugs on aging of mice using low-frequency in vivo electron spin resonance (ESR) spectroscopy.(1) We have employed the ESR spin trapping technique in vivo to detect the formation of the 5,5-dimethyl-1-pyrroline-N-oxide (DMPO)/hemoglobin thiyl free radical in rats following administration of either hydrazine or phenylhydrazine. Six line, strongly immobilized ESR spectra of hemoglobin thiyl radicals were observed in rats by L-band ESR spectrometer.(2) Non-invasive detection of nitric oxide (NO) which is generated by induced NO synthase : We have carried out direct, real-time, in vivo measurement of NO in mice using the water soluble metal chelator complex, N-methyl-D-glucamine dithiocarbamate (MGD), and Fe (II) as monitored by ESR at L-band microwave frequency. The three-line ESR spectrum from the product [(MGD)_2-Fe (II)-NO] was obtained non-invasively in lipopolysaccharide (LPS)-treated mice. The spectrum was markedly suppressed by the administration, prior to LPS injection, of phenyl N-tert-butyl nitrone (PBN), an inhibitor of the expression of induced no synthase.(3) In vivo ESR measurements of [(MGD)_2-Fe (II)-NO] at several regions in the body (from the head to the tail) indicated that the NO was generated mostly in the upper abdomen near the liver. The concentration of NO complex detected in the liver was about 100 mu M at maximum.