Abstract
Effects of external calcium on acetylcholine-induced increases in membrane capacitance and conductance were investigated with the patch-clamp technique in combination with the phase-sensitive detection method, in single dialysed pancreatic acinar cells of rats. Both increases depended on an increase in [Ca2+]i, and a high concentration of EGTA in the cell-dialysing solution made ACh ineffective. In acinar cells exposed to a bathing solution containing the normal concentration of Ca2+ (2.5 mM CaCl2), the increase in membrane capacitance was transient and synchronous with that in membrane conductance (current) in response to 0.2 μM acetylcholine. However, in a bathing solution without CaCl2 and with EGTA (0.2 mM), the increase in membrane capacitance was sustained after the membrane conductance recovered to the original level during the ACh-stimulation. The evidence suggests that external calcium facilitates either the resealing of the fusion- or fission-pores formed at the contact between the secretory granule and the luminal cell membrane, or the membrane retrieval (endocytosis) in Ca2+-dependent exocytosis.
Original language | English |
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Pages (from-to) | 438-440 |
Number of pages | 3 |
Journal | Pflügers Archiv European Journal of Physiology |
Volume | 413 |
Issue number | 4 |
DOIs | |
Publication status | Published - 1989 Feb 1 |
Keywords
- Exocytosis
- External calcium
- Internal calcium
- Membrane capacitance
- Pancreatic acinar cell
ASJC Scopus subject areas
- Physiology
- Clinical Biochemistry
- Physiology (medical)