Enhancement of photorepair of ultraviolet-induced pyrimidine dimers by preillumination with fluorescent light in the goldfish cell line. The relationship between survival and yield of pyrimidine dimers.
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.
Yasuhira
S
S
Laboratory of Radiation Biology, Faculty of Science, University of Tokyo, Japan.
Mitani
H
H
Shima
A
A
D000818:Animals; D002460:Cell Line; D004247:DNA / Q000528:radiation effects; D004249:DNA Damage; D004260:DNA Repair / Q000528:radiation effects*; D004307:Dose-Response Relationship, Radiation; D005453:Fluorescence; D006054:Goldfish; D008027:Light; D011740:Pyrimidine Dimers; D014466:Ultraviolet Rays
D011740:Pyrimidine Dimers; D004247:DNA