Hara H, Moriki T, Miyao M, Enzan H, Kutsukake F, Yamane T
Acta Pathol Jpn. 1982 Jul;32(4):595-603. doi: 10.1111/j.1440-1827.1982.tb02060.x.
The ultracytochemical acridine orange (AO) method has been employed to demonstrate DNA template activity within experimental brain tumors induced by transplacental administration ethylnitrosourea (ENU) in Sprague-Dawley rats. Ultrastructural examination revealed that acridine orange binds to DNA exclusively within the active extended euchromatin portion of the cell nucleus of brain tumor and of foci of atypical cell proliferation. No AO reaction products were visible in the non-neoplastic cell nuclei adjacent to the brain tumors. The percentages of AO positive cells in brain tumor cells in rats given an intraperitoneal injection of 3H-thymidine 1 hr before sacrifice were between 2.4% and 8.0%. The average number of AO chromatin reaction products per single section of a cell nucleus varied between 7 and 21. The ratios of areas of euchromatin to heterochromatin were found to be slightly larger in AO positive nuclei then in AO negative nuclei in each of the tumors. The present results suggested that rat brain tumors induced by transplacental administration ENU exhibit de-repression of DNA template normally repressed in the adult state. The usefulness of this method for study on the development of experimental brain tumors is briefly discussed.
采用超微细胞化学吖啶橙（AO）法，来证明经胎盘给予乙基硝基脲（ENU）诱导的实验性脑肿瘤内的DNA模板活性，该实验以Sprague-Dawley大鼠为对象。超微结构检查显示，吖啶橙仅与脑肿瘤细胞核及非典型细胞增殖灶的活性伸展常染色质部分内的DNA结合。在脑肿瘤附近的非肿瘤细胞核中未见AO反应产物。在处死前1小时腹腔注射3H-胸腺嘧啶核苷的大鼠脑肿瘤细胞中，AO阳性细胞的百分比在2.4%至8.0%之间。每个细胞核单切片上AO染色质反应产物的平均数量在7至21之间。发现在每个肿瘤中，AO阳性细胞核的常染色质与异染色质面积之比略大于AO阴性细胞核。目前的结果表明，经胎盘给予ENU诱导的大鼠脑肿瘤表现出成年状态下正常受抑制的DNA模板的去抑制。简要讨论了该方法在实验性脑肿瘤发展研究中的实用性。
