Related Experiment Video
Updated: May 4, 2026

The Mesenteric Lymph Duct Cannulated Rat Model: Application to the Assessment of Intestinal Lymphatic Drug Transport
Published on: March 6, 2015
Acid transport through channels in the mucous layer of rat stomach
M Johansson1, I Synnerstad, L Holm
1Department of Physiology, Uppsala University, Uppsala, Sweden. Mia.Johansson@Fysiologi.uu.se
Background & Aims:
We have reported previously that secreted acid moves through the mucous layer in restricted areas above the gastric crypts. The aim of this study was to visualize and study the dynamics of this event.
Methods:
Anesthetized rats prepared for intravital microscopy of the gastric mucosa were divided in the following groups with respect to acid secretion: spontaneous; stimulated (pentagastrin, 40 microg. kg(-1). h(-1)); transiently inhibited (omeprazole, 400 micromol. kg(-1) for 7 days); and totally inhibited (omeprazole, 3 x 200 micromol. kg(-1) for 7 days). The mucus was stained with Congo red (blue, pH < 3; red, pH > 5.2), and photographs were taken through a stereomicroscope.
Results:
During acid secretion, blue-colored crypt openings with attached thread-like (5-7 microm wide) structures (designated channels) were seen passing from the crypt openings through the mucus to the lumen. Red-colored channels and crypt openings were observed when acid secretion was transiently inhibited. Red-colored crypt openings but no channels were found after total inhibition of acid secretion for a week.
Conclusions:
The results suggest that secreted acid is transported through channels within the mucus. These channels are probably created by the high intraglandular pressure pushing acid and glandular mucus into the gel.
More Related Videos
Related Concept Videos
Stomach pH Regulation
The acid-secreting gastric mucosal epithelial cells (parietal cells) lining the stomach lumen maintain the low pH in the lumen. Numerous ion transporters and channels on these parietal...
Transcellular Transport of Solutes
Glucose Absorption Into the Small Intestine
Carbohydrate Absorption
After being swallowed, the partially digested carbohydrates mix with gastric secretions in the stomach. However, the acidic environment...
Carrier-Mediated Transport
Active transport involves two types of membrane-spanning transporters: uptake and efflux. Uptake transporters are expressed in the small...
Methods for Studying Drug Absorption: In situ
The Doluisio method involves perfusing a prepared segment of a rat's small intestine with a solution of radiolabeled drug and a non-absorbable marker. This helps to differentiate between absorbed and non-absorbed drug concentrations. The intestinal segment is connected at both ends using tubing and syringes,...

