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Technical note: fluorescein as an indicator of enteric mucosal barrier function in preruminant lambs
Audrey F Duff1, Lisa R Bielke1, Alejandro E Relling1
1Department of Animal Sciences, The Ohio State University, Wooster, OH.
Journal of Animal Science
|June 22, 2020
Summary
Fluorescein effectively indicates increased intestinal permeability in preweaned lambs under stress. However, it is not a reliable marker in lambs with developed rumens, unlike fluorescein isothiocyanate dextran (FITC-d).
Area of Science:
- Veterinary Medicine
- Animal Physiology
- Gastroenterology
Background:
- Increased intestinal permeability is linked to physiological stress responses, negatively impacting animal health and performance.
- Fluorescein isothiocyanate dextran (FITC-d) is an established marker for enteric inflammation and mucosal barrier function.
- Fluorescein, a smaller and more economical molecule, presents a potential alternative to FITC-d for assessing gut barrier integrity.
Purpose of the Study:
- To compare the efficacy of fluorescein and FITC-d as indicators of intestinal permeability in pre- and postweaned lambs.
- To evaluate the impact of dexamethasone-induced physiological stress on intestinal permeability in lambs using these markers.
Main Methods:
- Two experiments were conducted involving pre- and postweaned lambs administered dexamethasone (Dex) or a control treatment.
- Lambs received either fluorescein or FITC-d orally, with plasma fluorescence measured at specified time points post-administration.
- Plasma fluorescence ratios (T1h/T0 or T2h/T0) were analyzed to assess enteric permeability.
Main Results:
- Experiment 1 (preweaned lambs) showed a significant increase in the fluorescein ratio for lambs treated with Dex, indicating increased intestinal permeability.
- Experiment 2 (postweaned lambs) found no significant differences in permeability markers between treatment groups for either fluorescein or FITC-d.
- These findings suggest fluorescein's utility is specific to the developmental stage of the lamb's digestive system.
Conclusions:
- Fluorescein shows promise as a cost-effective marker for assessing enteric permeability in preruminant lambs experiencing physiological stress.
- Fluorescein is not a suitable indicator of intestinal permeability in lambs with fully developed rumens.
- Further research may explore FITC-d's applicability across different lamb developmental stages and stress conditions.
