Acid secretion by frog gastric mucosa is electroneutral.

Area of Science:

• Physiology
• Pharmacology
• Gastroenterology

Background:

• The gastric proton pump is crucial for acid secretion.
• Understanding its mechanism is key to treating acid-related disorders.

Purpose of the Study:

• To investigate the action of omeprazole, a novel gastric proton pump inhibitor.
• To elucidate the electrogenic nature of the gastric proton pump in frog gastric mucosa.

Main Methods:

• Utilized intact frog gastric mucosa for experiments.
• Administered omeprazole and measured acid secretion.
• Assessed tissue conductance and transtissue potential difference under various conditions.
• Investigated reversibility of inhibition with glutathione and 2-mercaptoethanol.

Main Results:

• Omeprazole inhibited gastric acid secretion, an effect reversible by glutathione or 2-mercaptoethanol.
• Inhibition occurred irrespective of the stimulus (histamine, carbachol, forskolin).
• Omeprazole did not alter tissue conductance, unlike thiocyanate or cimetidine.
• Omeprazole increased potential difference and short-circuit current in chloride solutions, but not in sulfate solutions.

Conclusions:

• The gastric proton pump in frog gastric mucosa appears to be electroneutral.
• Omeprazole's mechanism of action differs from other inhibitors like thiocyanate and cimetidine regarding its effect on tissue conductance.