title: A new method to measure intestinal secretion using fluorescein isothiocyanate-inulin in small bowel of rats.
abstract: BACKGROUND
  Small intestine ischemia can be seen in various conditions such as intestinal transplantation. To further understand the pathologic disruption in ischemia-reperfusion injury, we have developed a method to measure fluid changes in the intestinal lumen of rats.
  
  
  METHODS
  Two 10-cm rat intestine segments were procured, connected to the terminal apertures of a perfusion device, and continuously infused with 3 mL of HEPES solution (control solution) containing 50 μM of fluorescein isothiocyanate (FITC)-inulin. The perfusion device consists of concentric chambers that contain the perfused bowel segments, which are maintained at 37°C via H₂O bath. The individual chamber has four apertures as follows: two fill and/or drain the surrounding HEPES solution on the blood side of the tissue. The others provide flow of HEPES solution containing FITC-inulin through the lumens. The experimental intestine was infused with the same solution with 100 μM of Forskolin. A pump continuously circulated solutions at 6 mL/min. Samples were collected at 15-min intervals until 150 min and were measured by the nanoflourospectrometer.
  
  
  RESULTS
  A mean of 6-μM decrease in the FITC-inulin concentration in the Forskolin-treated experimental intestine was observed in comparison with that in the control intestine. The FITC-inulin count dilution in the experimental intestine is a result of an increase of fluid secretion produced by the effect of Forskolin, with P values <0.0001.
  
  
  CONCLUSIONS
  We demonstrate that it is possible to measure luminal fluid changes over time using our new modified perfusion system along with FITC-inulin to allow real-time determinations of fluid and/or electrolyte movement along the small intestine.
authors.affiliation: Department of Surgery, Yale University School of Medicine, New Haven, Connecticut.
authors.forename: Armando Salim
authors.initials: AS
authors.lastname: Munoz-Abraham
authors.affiliation: Department of Surgery, Yale University School of Medicine, New Haven, Connecticut.
authors.forename: Sami
authors.initials: S
authors.lastname: Judeeba
authors.affiliation: Department of Surgery, Yale University School of Medicine, New Haven, Connecticut.
authors.forename: Abedalrazaq
authors.initials: A
authors.lastname: Alkukhun
authors.affiliation: Department of Surgery, Yale University School of Medicine, New Haven, Connecticut.
authors.forename: Tariq
authors.initials: T
authors.lastname: Alfadda
authors.affiliation: Department of Surgery, Yale University School of Medicine, New Haven, Connecticut.
authors.forename: Roger
authors.initials: R
authors.lastname: Patron-Lozano
authors.affiliation: Department of Surgery, Yale University School of Medicine, New Haven, Connecticut.
authors.forename: Manuel I
authors.initials: MI
authors.lastname: Rodriguez-Davalos
authors.affiliation: Department of Surgery, Yale University School of Medicine, New Haven, Connecticut. Electronic address: john.geibel@yale.edu.
authors.forename: John P
authors.initials: JP
authors.lastname: Geibel
mesh_terms: D000818:Animals; D016650:Fluorescein-5-isothiocyanate / Q000031:analogs & derivatives*; D005456:Fluorescent Dyes; D007419:Intestinal Secretions / Q000502:physiology*; D007421:Intestine, Small / Q000503:physiopathology*; D007444:Inulin / Q000031:analogs & derivatives*; D008297:Male; D010477:Perfusion; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley; D015427:Reperfusion Injury / Q000503:physiopathology*; D013050:Spectrometry, Fluorescence
chemical_list: C584353:FITC-inulin; D005456:Fluorescent Dyes; D007444:Inulin; D016650:Fluorescein-5-isothiocyanate
keywords: Cyclic nucleotides; Fluid secretion; Fluorescence; Forskolin; Intestinal transplant; Ischemia