A new method to measure intestinal secretion using fluorescein isothiocyanate-inulin in small bowel of rats

• Published in: The Journal of surgical research Vol. 197; no. 2; pp. 225 - 230
• Main Authors: Munoz-Abraham, Armando Salim, MD, MBEE, Judeeba, Sami, MD, Alkukhun, Abedalrazaq, MD, Alfadda, Tariq, MD, Patron-Lozano, Roger, MD, Rodriguez-Davalos, Manuel I., MD, FACS, Geibel, John P., MD, DSc, MSc, AGAF
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01-08-2015
• Subjects: Animals; Cyclic nucleotides; Fluid secretion; Fluorescein-5-isothiocyanate - analogs & derivatives; Fluorescence; Fluorescent Dyes; Forskolin; Intestinal Secretions - physiology; Intestinal transplant; Intestine, Small - physiopathology; Inulin - analogs & derivatives; Ischemia; Male; Perfusion; Random Allocation; Rats; Rats, Sprague-Dawley; Reperfusion Injury - physiopathology; Spectrometry, Fluorescence; Surgery; Fluorescence; Intestinal transplant; Ischemia; Cyclic nucleotides; Fluid secretion; Forskolin
• ISSN: 0022-4804; 1095-8673
• DOI: 10.1016/j.jss.2015.02.049

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 H2 O 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.