Comparison of electrogenic glucose transport processes and permeability between proximal and distal jejunum of laying hens

ABSTRACT

1. The current objective was to assess (1) differences in mucosal transepithelial short-circuit current (I_sc) and tissue conductance (G_T), (2) the effect of a glucose stimulus and (3) epithelial paracellular permeability in the proximal and distal jejunum of laying hens.

2. Proximal and distal jejunal segments used in the Ussing chambers were collected at 9 ± 0.5 and 73 ± 3.4% (SEM) of jejunal length, respectively. The proximal jejunal mucosa showed a small negative I_sc (−1.3 µA/cm²), whereas the distal jejunum had a higher I_sc (32.9 µA/cm²). Similarly, G_T was 2.5-fold greater in the distal compared to the proximal jejunum.

3. Increased paracellular permeability in the distal jejunum was displayed as demonstrated by a 5-fold higher mucosal to serosal flux of fluorescein isothiocyanate and horseradish peroxidase, representing molecules of low and high molecular weight, respectively.

4. Addition of glucose to the mucosal side (5 mmol/l, final concentration in the chamber) to stimulate an absorptive effect caused 3-fold greater G_T in the distal compared to the proximal jejunum.

5. In conclusion, the present results supported site-specific electrogenic transport processes for the jejunal mucosa of laying hens. Therefore, precise description of the jejunal site may contribute to an improved comparability of electrophysiological data.

KEYWORDS:

• Laying hens
• intestinal permeability
• short-circuit current
• tissue conduction

Disclosure statement

No potential conflict of interest was reported by the authors.