Extracellular ATP elevates intracellular free calcium in rat parotid acinar cells Academic Article Article uri icon

Overview

MeSH Major

  • Ampulla of Vater
  • Balloon Occlusion
  • Common Bile Duct Diseases
  • Endoscopy, Digestive System
  • Hemorrhage
  • Stents

abstract

  • The effect of extracellular ATP on intracellular free Ca2+ was characterized in quin2-loaded parotid acinar cells. ATP specifically increased the intracellular Ca2+ concentration six-fold above a basal level of 180 nM. Of other purine nucleotides tested, only adenylylthiodiphosphate (ATP gamma S) had significant activity. ATP and the muscarinic agonist carbachol increased intracellular Ca2+ even in the absence of extracellular Ca2+. Both agonists stimulated K+ release, which was followed by reuptake of K+, even in the continued presence of agonist. In the absence of Mg2+, ATP was much more potent but no more efficacious in elevating intracellular Ca2+, suggesting that ATP4- is the active species. The effect of ATP was reversed by removal with hexokinase, arguing against a role for an active contaminant of ATP and against a non-specific permeabilizing effect of extracellular ATP. Lactate dehydrogenase release was unaffected by a maximally effective concentration of ATP. These observations are consistent with a possible neurotransmitter role for ATP in the rat parotid gland.

publication date

  • December 16, 1987

Research

keywords

  • Academic Article

Identity

Digital Object Identifier (DOI)

  • 10.1016/0006-291X(87)90399-8

PubMed ID

  • 3426590

Additional Document Info

start page

  • 523

end page

  • 30

volume

  • 149

number

  • 2