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Lack of "hemichannel" activity in insulin-producing cells

Scemes, Eliana
Spray, David C.
Published in Cell communication & adhesion. 2008, vol. 15, no. 1, p. 143-154
Abstract Connexins and pannexins have been implicated in the formation of "hemichannels," which may account for the uptake and release of membrane-impermeant molecules in single cells. The in vivo existence of "hemichannels" and their protein composition is still debated. Investigations on these matters are complicated by the lack of adequate negative controls. In search for such essential controls, the authors have investigated transformed (MIN6 line) and primary insulin-producing cells. Here, the authors report that these cells, which express Cx36 and pannexin 1, cannot be shown to display functional "hemichannels," as evaluated by (1) uptake of the membrane-impermeant tracer ethidium bromide, whether in the presence or absence of extracellular Ca(2+), following stimulation of P2X(7) receptors, and after exposure to hypotonic medium; and (2) lack of exocytosis-independent release of endogenous ATP. Moreover, electrophysiological recordings indicated the absence of carbenoxolone-sensitive pannexin 1 currents evoked by membrane potentials above +30 mV. Thus, insulin-producing cells are expected to provide a useful tool in the further characterization of hemichannel composition, properties, and physiological relevance.
Keywords AnimalsCell Line, TransformedCell Line, TumorCells, CulturedConnexins/metabolismInsulin-Secreting Cells/metabolismMembrane Potentials/physiologyMiceMice, Inbred C57BLMicroscopy, Confocal
PMID: 18649186
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Research group Couplage cellulaire et connexines (136)
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SCEMES, Eliana et al. Lack of "hemichannel" activity in insulin-producing cells. In: Cell communication & adhesion, 2008, vol. 15, n° 1, p. 143-154. doi: 10.1080/15419060802014255 https://archive-ouverte.unige.ch/unige:1918

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Deposited on : 2009-06-09

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