@article{oai:hsuh.repo.nii.ac.jp:00007284, author = {賀来, 亨 and 中出, 修 and 吉川, 泰子 and 八重樫, 和秀 and 大内, 知之 and 舘山, 美樹 and 阿部, 英二 and 菅野, 秀俊 and 江戸, 稔 and 奥山, 富三}, issue = {2}, journal = {東日本歯学雑誌}, month = {Dec}, note = {P(論文), This study describes the kinetics of induction and reinduction of GGT-stained cell populations (GGT-positive foci) induced in hamster cheek pouch epithelium by experimental protocols. The animals were divided into five groups and Groups 1,2,3 , and 4 were treated with biweekly topical applications of DMBA for 1,2,3 , and 5 weeks respectively (Phase 1 ). Then animals left untreated for 10 weeks (Phase 2 ), followed by three topical applications of DMBA a Monday-Friday-Monday sequence (Phase 3). Group 5 received the Phase 3 treatment only. GGT stained cells appeared rapidly in the epithelium of hamster cheek pouches treated by biweekly applications of DMBA. GGT-positive foci was only rarely detected in animals left untreated for the additional 10 weeks after completion of Phase 1. However, 3 applications of DMBA (Phase 3) resulted in the rapid formation of numerous GGT-positive foci in animals treated lOweeks previously with applications of DMBA (Phase 1 ) in all experimental groups. The Phase 3 treatment alone induced only 130 ± 50 GGT-positive foci per 10cm^2. The Resumption of the DMBA treatment appeared to reinduce GGT in occulted (unstained) foci which were present during the 10 weeks. A comparison of the size distribution of the foci at the completion of each treatment phase also suggests that the occulted (unstained) foci do not undergo further lateral growth during the 10-week treatment interval. The results suggest that a brief series of 3 DMBA applications reinduced GGT histochemical activity in occulted (unstained) foci which had lost enzyme activity. The expression of GGT in the majority of the foci is a transient metabolic phenomenon associated with DMBA exposure, whereas the induction of the foci is a persistent and possibly permanent consequence of prior DMBA exposure.}, pages = {143--151}, title = {<原著>ハムスター頬嚢におけるDMBA再塗布によるGGT陽性巣の再誘導について}, volume = {5}, year = {1986} }