Yasuhira S, Mitani H, Shima A
Laboratory of Radiation Biology, Faculty of Science, University of Tokyo, Japan.
Photochem Photobiol. 1992 Jan;55(1):97-101. doi: 10.1111/j.1751-1097.1992.tb04214.x.
The enhancement of photorepair of UV-induced pyrimidine dimers by preillumination with fluorescent light, previously reported with RBCF-1 cells derived from caudal fin of a goldfish, was studied in terms of clonogenic ability and yields of dimers. In the logarithmic growth phase, the ability of photorepair increased with the time after preillumination, reached a maximum at 8 h, and gradually declined. At 8 h, the dose decrement with the photorepair-treatment for 20 min at 7.5 J/m2 UV increased by preillumination for 1 h from 1.6 to 3.1 J/m2 in terms of restoration of survival and from 1.2 to 4.3 J/m2 in terms of the disappearance of dimers. Incubation of the preilluminated cells in the medium containing cycloheximide (0.5 microgram/mL) after preillumination until UV-irradiation diminished their enhancement of photorepair. In the density-inhibited state, the ability of photorepair was higher than in the log phase, and it was hardly enhanced by preillumination.
先前报道过用荧光灯预照射可增强紫外线诱导的嘧啶二聚体的光修复作用，该作用在源自金鱼尾鳍的RBCF-1细胞中得到证实。本研究从克隆形成能力和二聚体产量方面对其进行了探究。在对数生长期，光修复能力随着预照射后的时间增加而增强，在8小时时达到最大值，随后逐渐下降。在8小时时，就存活率恢复而言，用7.5 J/m²紫外线进行20分钟光修复处理时，预照射1小时使剂量减少量从1.6 J/m²增加到3.1 J/m²；就二聚体消失而言，剂量减少量从1.2 J/m²增加到4.3 J/m²。预照射后，将细胞在含有环己酰亚胺（0.5微克/毫升）的培养基中孵育直至紫外线照射，这会减弱它们的光修复增强作用。在密度抑制状态下，光修复能力高于对数期，并且预照射几乎不会增强其光修复能力。
