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Updated: Aug 25, 2026
Ex Vivo Intestinal Sacs to Assess Mucosal Permeability in Models of Gastrointestinal Disease
Published on: February 9, 2016
Influence of phosphate, sulfonic, and sulfamic acids on sulfoconjugate release in the vascularly perfused mouse small
Abstract:
An in vitro vascularly and luminally perfused preparation of the murine small intestine was used to investigate the interference of isethionate, cyclamate and HEPES (N-2-hydroxyethylpiperazine-N'-2-ethanesulfonic acid) with the luminal transport of the isoprenaline-sulfoconjugate as well as with the basolateral transport of naphthol-sulfoconjugate. The sulfonates and sulfamates when administered from the luminal as well as from the contraluminal side of the epithelium inhibited the transport of isoprenaline-sulfoconjugate. Inhibition of the naphthol-sulfoconjugate transport across the contraluminal epithelial membrane was less pronounced, but a countertransport phenomenon could be induced with cyclamate in the vascular medium. The presence of phosphate at the luminal side is essential for the transport of the isoprenaline-sulfoconjugate across the luminal membrane. This is not the case for bicarbonate. The conclusion is drawn that different transport systems for sulfoconjugates exist in the luminal and in the contraluminal membranes of the intestinal mucosa, which can be inhibited by structurally related compounds. The luminal transport system can be activated from the luminal side by phosphate.
Insights
This study reveals distinct intestinal transport systems for sulfoconjugates. Different compounds can inhibit these systems, with luminal transport requiring phosphate activation.
Area of Science:
- Pharmacology
- Gastroenterology
- Molecular Biology
Background:
- The intestinal absorption of sulfoconjugates is crucial for drug metabolism and nutrient transport.
- Understanding the specific mechanisms and transporters involved in intestinal sulfoconjugate handling is essential.
Purpose of the Study:
- To investigate the interference of specific compounds with luminal and basolateral transport of sulfoconjugates in the murine small intestine.
- To elucidate the role of phosphate and bicarbonate in luminal sulfoconjugate transport.
Main Methods:
- Utilized an in vitro vascularly and luminally perfused murine small intestine model.
- Assessed the inhibition of isoprenaline-sulfoconjugate luminal transport and naphthol-sulfoconjugate basolateral transport.
- Investigated the effects of isethionate, cyclamate, and HEPES on these transport processes.
Main Results:
- Sulfonates and sulfamates inhibited isoprenaline-sulfoconjugate transport from both luminal and contraluminal sides.
- Naphthol-sulfoconjugate transport inhibition was less pronounced, but cyclamate induced countertransport.
- Phosphate was essential for luminal isoprenaline-sulfoconjugate transport, while bicarbonate was not.
Conclusions:
- Distinct transport systems for sulfoconjugates exist in the luminal and contraluminal membranes of the intestinal mucosa.
- Structurally related compounds can inhibit these separate transport systems.
- The luminal sulfoconjugate transport system is activated by luminal phosphate.
