title: Pharmacokinetics and organ distribution of fluorescein in experimental pigs: an input study for confocal laser endomicroscopy of the gastrointestinal tract.
abstract: OBJECTIVE
  Confocal laser scanning endomicroscopy (CLSE) is a diagnostic technology that produces virtual histology of the mucosal layer using fluorescence technique. Fluorescein (FSC) is the most commonly used fluorescence agent. Fluorescence light coming from a horizontal special focal plane is detected during confocal laser endomicroscopy of the gastrointestinal tract. FSC causes intensive yellowish discoloration of tissues, including skin and mucous membranes. This pre-clinical study was aimed to evaluate the tissue distribution and pharmacokinetics of FSC after its intravenous administration.
  
  
  METHODS
  The study was performed in an adult experimental pig. A reversed-phase high-performance liquid chromatographic method with fluorescence detection was used for the determination of fluorescein in blood plasma and tissue samples.
  
  
  CONCLUSIONS
  The pharmacokinetic study of fluorescein determined the optimum time interval for diagnostic scanning (5-10 min.) The biodistribution study of fluorescein (aimed on the potential organ accumulation) proved the high concentration in the renal system followed by levels in bile > lung > adipose tissue > all other organs (including gastrointestinal wall) and these were relatively similar to each other. Fluorescein has a significantly low distribution in the brain (contrast with the level in adipose tissue indicates the low ability to penetrate the blood-brain barrier).
authors.affiliation: Institute of Experimental Biopharmaceutics, Joint Research Centre of PRO.MED.CS Praha a.s. and the Czech Academy of Sciences, Czech Republic. kunes@uebf.cas.cz
authors.forename: Martin
authors.initials: M
authors.lastname: Kunes
authors.forename: Jaroslav
authors.initials: J
authors.lastname: Kvetina
authors.forename: Jana
authors.initials: J
authors.lastname: Malakova
authors.forename: Jan
authors.initials: J
authors.lastname: Bures
authors.forename: Marcela
authors.initials: M
authors.lastname: Kopacova
authors.forename: Stanislav
authors.initials: S
authors.lastname: Rejchrt
mesh_terms: D000273:Adipose Tissue / Q000166:cytology / Q000378:metabolism; D000818:Animals; D001812:Blood-Brain Barrier; D001921:Brain / Q000166:cytology / Q000378:metabolism; D005260:Female; D019793:Fluorescein / Q000008:administration & dosage / Q000493:pharmacokinetics*; D005456:Fluorescent Dyes / Q000008:administration & dosage / Q000493:pharmacokinetics*; D041981:Gastrointestinal Tract / Q000166:cytology / Q000378:metabolism*; D007275:Injections, Intravenous; D007668:Kidney / Q000166:cytology / Q000378:metabolism; D008168:Lung / Q000166:cytology / Q000378:metabolism; D018613:Microscopy, Confocal; D023421:Models, Animal; D013552:Swine
chemical_list: D005456:Fluorescent Dyes; D019793:Fluorescein