title: Protoporphyrin-IX distribution and photodynamic effect in rat oesophagus after aminolaevulinic acid administration.
abstract: BACKGROUND
  Photodynamic therapy (PDT) is a method for local and selective tumour destruction achieved by the action of light on a photosensitizing drug.
  
  
  METHODS
  We investigated the distribution of 5-amino-laevulinic acid (ALA)-induced protoporphyrin-IX fluorescence in rat oesophagus by fluorescence microscopic examination and then studied the effects of PDT.
  
  
  RESULTS
  The highest level of fluorescence was achieved in the mucosa after 4 h of 300 mg/kg ALA administration. A clear difference in fluorescence between mucosa and muscularis was found in all samples except those taken 24 h after ALA administration. PDT with ALA caused destruction of the mucosal and, partly, submucosal layers of the oesophagus without damaging the muscularis layer.
  
  
  CONCLUSIONS
  According to our results with microscopic fluorescence kinetics and the preliminary results of PDT, selective destruction of the superficial layer of the rat oesophagus is achieved with PDT after ALA administration.
authors.affiliation: Dept. of Surgery, Kuopio University Hospital, Finland.
authors.forename: K
authors.initials: K
authors.lastname: Mäkinen
authors.forename: S
authors.initials: S
authors.lastname: Grönlund-Pakkanen
authors.forename: M
authors.initials: M
authors.lastname: Tiirikainen
authors.forename: P
authors.initials: P
authors.lastname: Nuutinen
authors.forename: A
authors.initials: A
authors.lastname: Kuusisto
authors.forename: E
authors.initials: E
authors.lastname: Alhava
mesh_terms: D000622:Aminolevulinic Acid / Q000494:pharmacology*; D000818:Animals; D004947:Esophagus / Q000187:drug effects* / Q000378:metabolism; D008297:Male; D008856:Microscopy, Fluorescence; D009092:Mucous Membrane / Q000187:drug effects; D009130:Muscle, Smooth / Q000187:drug effects; D010778:Photochemotherapy; D017319:Photosensitizing Agents / Q000493:pharmacokinetics* / Q000494:pharmacology*; D011524:Protoporphyrins / Q000493:pharmacokinetics* / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D013997:Time Factors
chemical_list: D017319:Photosensitizing Agents; D011524:Protoporphyrins; D000622:Aminolevulinic Acid; C028025:protoporphyrin IX