J Korean Med Sci.  2000 Aug;15(Suppl):S36-S37. 10.3346/jkms.2000.15.S.S36.

[Na+]i, [K+]i and [Cl-]i regulation of exocytosis in guinea-pig antral mucous cells

• Nakahari T
• Fujiwara S
• Shimamoto

• KMID: 1026944
• DOI: http://doi.org/10.3346/jkms.2000.15.S.S36

Abstract

Effects of intracellular Na+, K+ and Cl- on Ca(2+)-regulated exocytosis activated by 10 microM acetylcholine (ACh) were studied in guinea-pig antral mucous cells which are permeabilized by nystatin treatment. Ca(2+)-regulated exocytotic events were modulated by [Na+]i, [K+]i and [Cl-]i via mediation of PTX-sensitive G proteins. Increases in [Na+]i and PTX inhibit G protein (G(Na)), which suppressed the exocytosis. Increases in [K+]i caused the exchange of G proteins (from G(Na) to G(K)) to increase, and GK evoked activation of the exocytosis and was inhibited by PTX. Increases in [Cl-]i and PTX inhibit G protein (G(Cl)), which stimulates exocytotic events. Based on these observations, the exocytosis in antral mucous cells were modulated by intracellular ions, concentration of which were increased or decreased by cell volume changes caused by Ach.

Keyword

Gastric Mucin; Acetylcholine; Nystatin; Pertussis Toxin; G Protein

MeSH Terms

Acetylcholine/pharmacology
Animal
Cell Membrane Permeability/drug effects
Exocytosis/physiology*
Exocytosis/drug effects
Gastric Mucosa/metabolism
Gastric Mucosa/cytology
Guinea Pigs
Hypertonic Solutions/pharmacology
Ionophores/pharmacology
Nystatin/pharmacology
Pertussis Toxins/pharmacology
Potassium/pharmacokinetics*
Pyloric Antrum/metabolism*
Pyloric Antrum/cytology
Sodium Chloride/pharmacokinetics*
Vasodilator Agents/pharmacology