Kondo T, Kodaira T, Kano E
Department of Experimental Radiology and Health Physics, Fukui Medical School, Japan.
Free Radic Res Commun. 1993;19 Suppl 1:S193-200. doi: 10.3109/10715769309056s193.
Recent sonochemical studies have revealed that active oxygen species are formed by pyrolysis of water molecules due to high temperature cavitation bubbles. When aqueous solutions of DNA were sonicated, single-strand breaks and double-strand breaks of DNA were observed. Formation of double-strand breaks due to mechanical effects of cavitation and formation of single-strand breaks mostly due to free radicals were indicated. The sonochemically generated radicals from DNA constituents due to H atom and OH radical reactions, and pyrolysis processes, were identified by spin trapping with 3,5-dibromo-2,6-dideuterio-4-nitrosobenzene sulfonate. When suspensions of mouse mammary carcinoma FM3A cells and aqueous solutions of 5,5-dimethyl-1-pyrroline-N-oxide (DMPO) were exposed to 1 MHz ultrasound in the presence of Ar, a good correlation between DMPO-OH formation and the cell killing induced by ultrasound were observed. Although single-strand breaks of DNA in the cells were observed at the maximum intensity of DMPO-OH formation and cell killing, double-strand breaks were not. Free radical formation by ultrasound in aqueous solutions and its relation to DNA strand breaks in vitro and in vivo are discussed.
最近的声化学研究表明，由于高温空化气泡导致水分子热解会形成活性氧物种。当对DNA水溶液进行超声处理时，会观察到DNA的单链断裂和双链断裂。结果表明，空化的机械作用导致双链断裂，而单链断裂主要是由自由基引起的。通过用3,5-二溴-2,6-二氘代-4-亚硝基苯磺酸盐进行自旋捕获，鉴定了由于H原子和OH自由基反应以及热解过程而从DNA成分中声化学产生的自由基。当在Ar存在下将小鼠乳腺癌FM3A细胞悬液和5,5-二甲基-1-吡咯啉-N-氧化物（DMPO）水溶液暴露于1 MHz超声时，观察到DMPO-OH的形成与超声诱导的细胞杀伤之间具有良好的相关性。尽管在DMPO-OH形成和细胞杀伤的最大强度下观察到细胞中DNA的单链断裂，但未观察到双链断裂。本文讨论了超声在水溶液中形成自由基及其与体外和体内DNA链断裂的关系。
