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Stimulus‐secretion coupling in pancreatic acinar cells: inhibitory effects of calcium removal and manganese addition on pancreozymin‐induced amylase release.
Author(s) -
Kanno T,
Nishimura O
Publication year - 1976
Publication title -
the journal of physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.802
H-Index - 240
eISSN - 1469-7793
pISSN - 0022-3751
DOI - 10.1113/jphysiol.1976.sp011370
Subject(s) - amylase , extracellular , chemistry , calcium , secretion , biophysics , stimulation , acinar cell , medicine , endocrinology , stimulus (psychology) , pancreas , enzyme , biochemistry , biology , psychology , organic chemistry , psychotherapist
The role of Ca ions in stimulus‐secretion coupling has been analysed in the isolated and perfused rat pancreas. 2. The omission of [Ca2+]O diminished but did not abolish the release of amylase in response to continuous stimulation with 5 m‐u. pancreozymin (Pz)/ml. The addition of Mn2+ (1‐0 mM) to this Ca‐deficient environment abolished the residual release of amylase. This was followed by a complete recovery of amylase output when the control [Ca2+]O was reestablished. 3. The addition of Mn2+ (1‐0 mM) to the extracellular environment containing 2‐5 mM‐Ca2+ reversibly inhibited the Pz‐induced release of amylase. 4. A kinetic scheme based on competition of Ca and Mn at a carrier in the acinar cell membrane could quantitatively explain the effects of Ca and Mn upon the Pz‐induced amylase release. 5. These results support the view that the Ca2+ influx into the acinar cells is the major contributor to the rise in [Ca2+]i which, in turn, mediates the processes in the stimulus‐secretion coupling in the exocrine pancreas, and suggest that the mode of Ca influx is a facilitated diffusion.