Microelectrode measurements of K+ and pH in rabbit gastric glands: effect of histamine.

Academic Article

Abstract

  • Conventional and liquid ion-exchange microelectrodes sensitive to K+ or pH were used to examine the response of isolated rabbit gastric glands to histamine. The epithelial cells were impaled across the basolateral membrane. The membrane potential averaged -6.1 +/- 0.6 mV and was unchanged after replacement of medium K+, Cl-, or Na+. The intracellular K+ activity (alpha iK) averaged 41.3 +/- 3.0 mM, indicating K+ accumulation by a factor of 6.8. Active accumulation of K+ was eliminated by ouabain. In contrast, histamine increased K+ activity to 55.3 +/- 3.9 mM. This stimulation was blocked by ouabain. In glands bathed in a Na+-free medium containing ouabain, addition of histamine elevated alpha iK from 12.5 +/- 0.7 to 17.1 +/- 1.1 mM. Isobutylmethylxanthine (10(-4) M) also elevated alpha iK. When impaled with pH-sensitive microelectrodes, glands exposed to histamine exhibited regions of acidity as low as pH 3. Acidification was also produced by histamine after medium Na+ had been replaced with choline. Picoprazole (H 149/94) blocked the effects of histamine on alpha iK and gland pH. The results are consistent with the view that histamine-induced acid secretion by gastric glands is associated with K+ uptake by a mechanism that is independent of Na+ transport but is inhibited by intracellular Na+. This is most likely the H+-K+-ATPase on the secretory surface of the gland cells. Evidence that some tissue K+ is bound or compartmentalized is also discussed.
  • Authors

  • Lockwood, Mary Katherine
  • Hersey, SJ
  • White, JF
  • Status

    Publication Date

  • April 1984
  • Published In

    Keywords

  • 1-Methyl-3-isobutylxanthine
  • 2-Pyridinylmethylsulfinylbenzimidazoles
  • Aminopyrine
  • Animals
  • Benzimidazoles
  • Gastric Juice
  • Gastric Mucosa
  • Histamine
  • Hydrogen-Ion Concentration
  • Membrane Potentials
  • Microelectrodes
  • Omeprazole
  • Ouabain
  • Potassium
  • Rabbits
  • Digital Object Identifier (doi)

    Pubmed Id

  • 6202153
  • Start Page

  • G433
  • End Page

  • G444
  • Volume

  • 246
  • Issue

  • 4 Pt 1