Ca2+-dependent unidirectional vesicular release detected with a carbon-fibre electrode in rat pancreatic acinar cell triplets

Yukinari Tomita, Gen Inooka, Hitoshi Shimada, Yoshio Maruyama

Research output: Contribution to journalArticlepeer-review

7 Citations (Scopus)

Abstract

An amperometric constant-voltage method for detection of serotonin oxidation currents was applied to pancreatic acinar cell triplets to determine the site of release of granular content following an increase in [Ca2+]i. The carbon fibre electrode, fabricated to be compatible with a conventional patch-clamp amplifier, was voltage-clamped at 600 mV exceeding the serotonin oxidation voltage, 300 mV. The electrode was placed on the different regions of cell surface of acinar cell triplets loaded with exogenous serotonin. Transient oxidation currents were detected only when the electrode was placed on the acinar lumen after stimulation with a Ca2+ ionophore, A23187, but never observed on the basal or lateral cell surface, or paracellular clefts. No such current responses were observed in the acinar cells without serotonin loading. The results indicate that the A23187-induced sustained increase in [Ca2+]i discharges serotonin specifically into the lumen, and provides direct evidence for the presence of Ca2+-dependent unidirectional release of granular contents in pancreatic acinar cells.

Original languageEnglish
Pages (from-to)69-75
Number of pages7
JournalPflügers Archiv European Journal of Physiology
Volume428
Issue number1
DOIs
Publication statusPublished - 1994 Aug 1

Keywords

  • Ca-dependent exocytosis
  • Carbon fibre electrode
  • Oxidation currents
  • Pancreatic acinar cells
  • Polarized secretion

ASJC Scopus subject areas

  • Physiology
  • Clinical Biochemistry
  • Physiology (medical)

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