title: [Absorption of recombinant hirudin in rats GI tract].
abstract: OBJECTIVE
  To investigate the absorption and distribution of recombinant hirudin-2 (rHV2) in the GI tract in rats after oral administration.
  
  
  METHODS
  Using HPLC, fluorescence spectrophotometry and confocal laser scanning microscopy to measure the amount of intact rHV2 absorbed into gastrointestinal mucosa and blood.
  
  
  RESULTS
  HPLC spectrum showed that there were intact rHV2 molecules in plasma after 1 h of oral administration. After oral administration for 3 h, 1.2%-26.8% of fluorescence was found in the GI tract in rats. Chromatographic analysis showed that 2.27%-38.75% of fluorescence recovered from the GI tract luminal contents and mucosa was eluted at the void volume of a Sephadex G-25 column. Microscopic examination showed that FITC-rHV2 was taken up throughout the whole small intestine but the ileum appeared to be a preferred site for FITC-rHV2 transport in rats.
  
  
  CONCLUSIONS
  rHV2 may partially survive in the GI lumen and subsequently absorbed in active form by gastrointestinal tract.
authors.affiliation: Department of Pharmaceutics, School of Pharmaceutical Science, Peking University, Beijing 100083, China.
authors.forename: Xue-ying
authors.initials: XY
authors.lastname: Yan
authors.forename: Xue-nong
authors.initials: XN
authors.lastname: Zhang
authors.forename: Qiang
authors.initials: Q
authors.lastname: Zhang
mesh_terms: D000284:Administration, Oral; D000818:Animals; D004064:Digestive System / Q000378:metabolism*; D005343:Fibrinolytic Agents / Q000008:administration & dosage / Q000493:pharmacokinetics*; D016650:Fluorescein-5-isothiocyanate; D006629:Hirudins / Q000008:administration & dosage / Q000493:pharmacokinetics*; D007082:Ileum / Q000378:metabolism / Q000648:ultrastructure; D007408:Intestinal Absorption; D007413:Intestinal Mucosa / Q000378:metabolism / Q000648:ultrastructure; D008297:Male; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley; D011994:Recombinant Proteins / Q000008:administration & dosage / Q000493:pharmacokinetics; D014018:Tissue Distribution
chemical_list: D005343:Fibrinolytic Agents; D006629:Hirudins; D011994:Recombinant Proteins; D016650:Fluorescein-5-isothiocyanate