ISSN:
1432-2013
Keywords:
Polarized secretion
;
Pancreatic acinar cells
;
Oxidation currents
;
Carbon fibre electrode
;
Ca2+-dependent exocytosis
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
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.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00374753
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