title: Ultrastructural assessment of the radioprotective effects of sodium selenite on parotid glands in rats.
abstract: The aim of this study was to assess the radioprotective effects of sodium selenite on parotid glands in rats by ultrastructural analysis of acinar cells. Four experimental groups were assessed; control, irradiated, selenium, and selenium/irradiated. The sodium selenite dose was 0.5 mg/kg, administered intraperitoneally 24 h before irradiation in the head and neck region with a single 15-Gy dose of gamma radiation. At 4, 8, 12, 48 and 72 h after irradiation, all animals were sacrificed and the parotid glands were removed. Radiation caused cellular changes from 4 h, and the organelles that presented the greatest alterations were the mitochondria and the secretion glands; nuclear alterations were also observed. Sodium selenite was found to have a radioprotective action, as the selenium/irradiated group presented with less damage when compared to the irradiated group. However, sodium selenite caused cellular alterations that were evident after 8 h, but with less damage when compared to those caused by radiation, which demonstrates a favorable risk-benefit for its use as a radioprotector. Thus, this research shows that sodium selenite has an effective radioprotective action in the parotid gland, which may contribute to the reduction of the adverse effects brought by the radiotherapy.
authors.affiliation: Department of Oral Diagnosis, Federal University of Pará, Brazil.
authors.forename: Fabrício M
authors.initials: FM
authors.lastname: Tuji
authors.forename: Maria Luiza dos A
authors.initials: ML
authors.lastname: Pontual
authors.forename: Silvana P
authors.initials: SP
authors.lastname: Barros
authors.forename: Solange M de
authors.initials: SM
authors.lastname: Almeida
authors.forename: Frab N
authors.initials: FN
authors.lastname: Bóscolo
mesh_terms: D000818:Animals; D005609:Free Radicals / Q000378:metabolism; D008297:Male; D010306:Parotid Gland / Q000528:radiation effects* / Q000648:ultrastructure; D011837:Radiation-Protective Agents / Q000627:therapeutic use*; D011879:Radiotherapy Dosage; D051381:Rats; D017208:Rats, Wistar; D018038:Sodium Selenite / Q000627:therapeutic use*
chemical_list: D005609:Free Radicals; D011837:Radiation-Protective Agents; D018038:Sodium Selenite