engleski

Imbalance between Apoptosis and Proliferation causes late Radiation Damage of Salivary Gland in Mouse

Severe xerostomia is common late radiation consequence, which occurs after irradiation of head and neck malignancies. The aim of the present study was to analyze apoptosis and proliferation and their relationship during late post irradiation phase. C57BL/6 mice were locally irradiated in head and neck region with a single dose of 7.5 and 15 Gy and their submandibular glands were collected at 40 and 90 days post irradiation. To identify apoptotic cells, TUNEL method and to detect proliferation, immunohistochemistry with proliferating cell nuclear antigen (PCNA) were used. Histological changes at day 40 were mild in contrast to day 90 when glands of irradiated mice showed severe atrophy, vacuolization and mononuclear infiltration. Acinar cells, granular and intercalated duct cells of mice irradiated with 7.5 and 15 Gy expressed higher apoptotic index than cells of unirradiated, control glands at both examined time points. At 40 days only in group irradiated with 7.5 Gy higher proliferation index in granular and intercalated duct cells was detected. At 90 days in both irradiated groups proliferation index for all cell types was similar to control. According to our results imbalance between apoptosis and proliferation caused by X-irradiation may be the reason for gland impairment during late post irradiation phase.

irradiation; salivary glands; late post irradiation phase; apoptosis; proliferation

nije evidentirano