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Basal and stimulated human gastric bicarbonate secretion
Scandinavian Journal of Gastroenterology. Supplement
|January 1, 1987
Summary
Human gastric bicarbonate secretion, a key defense against acid, is actively regulated. Vagal stimulation and prostaglandins significantly increase this secretion, crucial for maintaining gastric mucosal integrity.
Area of Science:
- Gastroenterology
- Physiology
- Mucosal Biology
Background:
- The gastric mucosa employs a mucus-bicarbonate barrier as a primary defense against luminal acid.
- Mucus and bicarbonate are produced by gastric mucus cells, with bicarbonate actively secreted via Cl-/HCO3- exchange.
Purpose of the Study:
- To quantify human gastric bicarbonate secretion using a novel computer-based system.
- To investigate the physiological regulation of gastric bicarbonate secretion by vagal stimulation and prostaglandins.
Main Methods:
- Utilized a computer-based system for continuous in vivo measurement of gastric pH and PCO2.
- Employed a gastric perfusion system in 24 healthy subjects.
- Administered sham feeding for vagal stimulation and 16,16 dimethyl prostaglandin E2 to assess secretory responses.
Main Results:
- Basal gastric bicarbonate secretion averaged 386 ± 31 mumol/h, with a 95% confidence interval of 103-669 mumol/h.
- Vagal stimulation (sham feeding) increased secretion by 63%, while prostaglandin E2 increased it by 214%.
- Vagal stimulation effects were independent of intragastric pH and blocked by anticholinergics; prostaglandin effects were not influenced by cyclooxygenase inhibition.
Conclusions:
- Human gastric bicarbonate secretion is a regulated process influenced by neural and hormonal pathways.
- Prostaglandins and vagal stimulation represent significant stimulators of gastric bicarbonate secretion, contributing to mucosal protection.