PuSH - Publication Server of Helmholtz Zentrum München

Speier, S.* ; Gjinovci, A.* ; Charollais, A.* ; Meda, P.* ; Rupnik, M.*

Cx36-mediated coupling reduces beta-cell heterogeneity, confines the stimulating glucose concentration range, and affects insulin release kinetics.

Diabetes 56, 1078-1086 (2007)
DOI PMC
Open Access Green as soon as Postprint is submitted to ZB.
We studied the effect of gap junctional coupling on the excitability of beta-cells in slices of pancreas, which provide a normal environment for islet cells. The electrophysiological properties of beta-cells from mice (C57Bl/6 background) lacking the gap junction protein connexin36 (Cx36(-/-)) were compared with heterozygous (Cx36(+/-)) and wild-type littermates (Cx36(+/+)) and with frequently used wild-type NMRI mice. Most electrophysiological characteristics of beta-cells were found to be unchanged after the knockout of Cx36, except the density of Ca(2+) channels, which was increased in uncoupled cells. With closed ATP-sensitive K(+) (K(ATP)) channels, the electrically coupled beta-cells of Cx36(+/+) and Cx36(+/-) mice were hyperpolarized by the membrane potential of adjacent, inactive cells. Additionally, the hyperpolarization of one beta-cell could attenuate or even stop the electrical activity of nearby coupled cells. In contrast, beta-cells of Cx36(-/-) littermates with blocked K(ATP) channels rapidly depolarized and exhibited a continuous electrical activity. Absence of electrical coupling modified the electrophysiological properties of beta-cells consistent with the reported increase in basal insulin release and altered the switch on/off response of beta-cells during an acute drop of the glucose concentration. Our data indicate an important role for Cx36-gap junctions in modulating stimulation threshold and kinetics of insulin release.
Impact Factor
Scopus SNIP
Altmetric
0.000
0.000
Tags
Annotations
Special Publikation
Hide on homepage

Edit extra information
Edit own tags
Private
Edit own annotation
Private
Hide on publication lists
on hompage
Mark as special
publikation
Publication type Article: Journal article
Document type Scientific Article
Language english
Publication Year 2007
HGF-reported in Year 0
ISSN (print) / ISBN 0012-1797
e-ISSN 1939-327X
Journal Diabetes
Quellenangaben Volume: 56, Issue: 4, Pages: 1078-1086 Article Number: , Supplement: ,
Publisher American Diabetes Association
Publishing Place Alexandria, VA.
Reviewing status Peer reviewed
Institute(s) Institute of Pancreatic Islet Research (IPI)
PubMed ID 17395748
Erfassungsdatum 2007-12-31