title: The relationship between the severity of radiation-induced oral mucositis and the myeloperoxidase levels in rats.
abstract: OBJECTIVE
  Oral mucositis is a common adverse reaction to radiotherapy for head and neck cancer, and there are concerns regarding a decreased quality of life in patients receiving radiotherapy. The purpose of this study was to investigate the relationship between the severity of radiation-induced oral mucositis and the myeloperoxidase (MPO) levels in irradiated tissues.
  
  
  METHODS
  Ninety-six F344 rats were divided into the following 4 groups: 10-Gy, 18-Gy, and 30-Gy irradiation groups, and a nonirradiation group. Oral mucositis was induced by the administration of single doses of radiation via exposure. After irradiation, the rats were evaluated on the basis of weight measurements, macroscopic findings according to a grading scale (Oral Mucositis Index [OMI]), and the results of tissue MPO assays.
  
  
  RESULTS
  Weights decreased whereas the OMI scores and MPO levels increased, depending on the dose of exposure. The Spearman rank correlation test showed a significant correlation between the OMI scores and the MPO levels in the tissues with a correlation coefficient of 0.824 (P < .01).
  
  
  CONCLUSIONS
  In this study, the MPO levels in the irradiated tissue were increased in the cases involving severe radiation-induced oral mucositis evaluated in rats using a grading scale.
authors: Graduate Student, Department of Oral and Maxillofacial Surgery, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan. Electronic address: Miya0331@me.com.
authors: Hironori
authors: H
authors: Miyamoto
authors: Assistant Professor, Department of Oral and Maxillofacial Surgery, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan.
authors: Takeo
authors: T
authors: Kanayama
authors: Clinical Fellow, Department of Oral and Maxillofacial Surgery, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan.
authors: Koichiro
authors: K
authors: Horii
authors: Assistant Professor, Department of Radiology, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan.
authors: Tatsuya
authors: T
authors: Kawai
authors: Assistant Professor, Department of Oral and Maxillofacial Surgery, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan.
authors: Tsukasa
authors: T
authors: Tsuchimochi
authors: Associate Professor, Department of Oral and Maxillofacial Surgery, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan.
authors: Toshio
authors: T
authors: Shigetomi
authors: Professor, Department of Radiology, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan.
authors: Yuta
authors: Y
authors: Shibamoto
authors: Professor, Department of Oral and Maxillofacial Surgery, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan.
authors: Yasuyuki
authors: Y
authors: Shibuya
mesh_terms: D000818:Animals; D004307:Dose-Response Relationship, Radiation; D005260:Female; D006258:Head and Neck Neoplasms / Q000532:radiotherapy; D009195:Peroxidase / Q000378:metabolism*; D011829:Radiation Dosage; D011832:Radiation Injuries / Q000209:etiology* / Q000473:pathology*; D051381:Rats; D011916:Rats, Inbred F344; D012720:Severity of Illness Index; D013280:Stomatitis / Q000209:etiology* / Q000473:pathology*; D014059:Tongue / Q000528:radiation effects
chemical_list: D009195:Peroxidase