title: Effective dose of 5-fluorouracil for myringotomy in rats.
abstract: BACKGROUND
  The purpose of this study is to compare the effects of two different doses of 5-fluorouracil (5-FU) on closure rates and histopathological findings in myringotomy to those of simple myringotomy with saline application.
  
  
  METHODS
  36 rats were divided into two study groups and a control group of 12 rats each. After bilateral myringotomy, we applied 5-FU 50 mg/ml in group A, 10 mg/ml in group B and saline in the control group for 10 minutes. Examination was made by otoendoscopy on days 1, 3, 5, 7, 10, 15, 20, 25. After the follow up examination, two rats from each group were randomly sacrificed on days 7, 15, 25 and 35. Both tympanic membranes were investigated for fibrosis and inflammation by light microscopy.
  
  
  RESULTS
  Most of the tympanic membranes from group B and the control group healed on the 10th day, but 16 myringotomies were patent in group A; by the 25th day, all myringotomies in all three groups were completely healed. The mean healing time was 14.62 days, 10.20 days and 10.40 days respectively in groups A, B and control. Fibrosis and inflammation were less in group A than in group B and the controls.
  
  
  CONCLUSIONS
  5-FU at a concentration of 50 mg/mL is effective in prolonging the patency of myringotomies in rat tympanic membranes, while a concentration of 10 mg/mL has no greater effect than a simple myringotomy procedure with saline application.
authors.affiliation: Department of ENT, Haydarpasa Training Hospital, Gülhane Military Medical Academy, Istanbul, Turkey. hcincik@ttnet.net.tr
authors.forename: Hakan
authors.initials: H
authors.lastname: Cincik
authors.forename: Atila
authors.initials: A
authors.lastname: Güngör
authors.forename: Omer
authors.initials: O
authors.lastname: Sağlam
authors.forename: Engin
authors.initials: E
authors.lastname: Cekin
authors.forename: Sükrü
authors.initials: S
authors.lastname: Yildirim
authors.forename: Ethem
authors.initials: E
authors.lastname: Poyrazoğlu
mesh_terms: D000818:Animals; D000963:Antimetabolites / Q000008:administration & dosage; D004305:Dose-Response Relationship, Drug; D005355:Fibrosis; D005472:Fluorouracil / Q000008:administration & dosage*; D007249:Inflammation / Q000517:prevention & control; D008876:Middle Ear Ventilation / Q000379:methods*; D010034:Otitis Media with Effusion / Q000188:drug therapy / Q000473:pathology / Q000601:surgery; D051381:Rats; D017207:Rats, Sprague-Dawley; D014432:Tympanic Membrane / Q000187:drug effects / Q000473:pathology / Q000601:surgery; D014945:Wound Healing / Q000187:drug effects
chemical_list: D000963:Antimetabolites; D005472:Fluorouracil