Document Detail

Unperturbed islet α-cell function examined in mouse pancreas tissue slices.
MedLine Citation:
PMID:  21078586     Owner:  NLM     Status:  MEDLINE    
Critical investigation into α-cell biology in health and diabetes has been sparse and at times inconsistent because of the technical difficulties with employing conventional strategies of isolated islets and dispersed single cells. An acute pancreas slice preparation was developed to overcome the enzymatic and mechanical perturbations inherent in conventional islet cell isolation procedures. This preparation preserves intra-islet cellular communication and islet architecture in their in situ native state. α-Cells within tissue slices were directly assessed by patch pipette and electrophysiologically characterized. The identity of the patched cells was confirmed by biocytin dye labelling and immunocytochemistry. α-Cells in mouse pancreas slices exhibited well-described features of I(Na) (excitable at physiological membrane potential), I(KATP), small cell size, low resting membrane conductance, and inducible low and high voltage-activated I(Ca), the latter correlating with exocytosis determined by capacitance measurements. In contrast to previous reports, our large unbiased sampling of α-cells revealed a wide range distribution of all of these parameters, including the amount of K(ATP) conductance, Na+ and Ca2+ current amplitudes, and capacitance changes induced by a train of depolarization pulses. The proposed pancreas slice preparation in combination with standard patch-clamping technique allowed large sampling and rapid assessment of α-cells, which revealed a wide distribution in α-cell ion channel properties. This specific feature explains the apparent inconsistency of previous reports on these α-cell ion channel properties. Our innovative approach will enable future studies into elucidating islet α-cell dysregulation occurring during diabetes.
Ya-Chi Huang; Marjan Rupnik; Herbert Y Gaisano
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Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't     Date:  2010-11-15
Journal Detail:
Title:  The Journal of physiology     Volume:  589     ISSN:  1469-7793     ISO Abbreviation:  J. Physiol. (Lond.)     Publication Date:  2011 Jan 
Date Detail:
Created Date:  2011-01-17     Completed Date:  2011-05-25     Revised Date:  2013-07-03    
Medline Journal Info:
Nlm Unique ID:  0266262     Medline TA:  J Physiol     Country:  England    
Other Details:
Languages:  eng     Pagination:  395-408     Citation Subset:  IM    
Institute of Medical Science, University of Toronto, Toronto, ON, Canada.
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MeSH Terms
Calcium / metabolism
Exocytosis / physiology*
Glucagon-Secreting Cells / physiology*
Ion Channel Gating / physiology
Membrane Potentials / physiology*
Pancreas / cytology*,  physiology
Potassium Channels / physiology
Grant Support
CGD76317//Canadian Institutes of Health Research
Reg. No./Substance:
0/Potassium Channels; 7440-70-2/Calcium

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

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