Intercellular communication: role of gap junctions in establishing the pattern of ATP-elicited Ca2+ oscillations and Ca2+- dependent currents in freshly isolated aortic smooth muscle cells

Article Article scientifique Article Intercellular communication: role of gap junctions in establishing the pattern of ATP-elicited Ca2+ oscillations and Ca2+- dependent currents in freshly isolated aortic smooth muscle cells eng 2005 author Fanchaouy Mohammed 543072 author Serir Karima 51281 author Meister J.J. author Beny Jean-Louis 26368 author Bytchkov Rostislav 134472 25-34 10.1016/j.ceca.2004.06.008 15541461 0143-4160 Cytosolic-free [Ca2+] was evaluated in freshly dissociated smooth muscle cells from mouse thoracic aorta by the ratio of Fura Red and Fluo 4 emitted fluorescence using confocal microscopy. The role of intercellular communication in forming and shaping ATP-elicited responses was demonstrated. Extracellular ATP (250 microM) elicited [Ca2+]i transient responses, sustained [Ca2+]i rise, periodic [Ca2+]i oscillations and aperiodic repetitive [Ca2+]i transients. Quantity of smooth muscle cells in the preparation responding to ATP with periodical [Ca2+]i oscillations depended on the density of isolated cells on the cover slip. ATP-elicited bursts of [Ca2+]i spikes in 66+/-7% of cells in dense and in 33+/-8.5% of cells in non-dense preparations. The number of cells responding to ATP with bursts of [Ca2+]i spikes decreased from 55+/-5% (n=84) to 14+/-3% (n=141) in dense preparations pretreated with carbenoxolone. Simultaneous measurement of [Ca2+]i and ion currents revealed a correlation between [Ca2+]i and current oscillations. ATP-elicited bursts of current spikes in 76% of cells regrouped in small clusters and in 9% of isolated cells. Clustered cells responding to ATP with current oscillations had higher membrane capacity than clustered cells with transient and sustained ATP-elicited responses. Lucifer Yellow (1% in 130 mM KCl) injected into one of clustered cells was transferred to the neighboring cell only when ATP-elicited oscillations. Fast application of carbenoxolone (100 microM) inhibited ATP (250 microM) elicited Ca2+-dependent current oscillations. Taken together these results suggest that the probability of ATP (250 microM) triggered cytosolic [Ca2+]i oscillations accompanied with K+ and Cl- current oscillations increased with the coupling of smooth muscle cells. Freshly isolated aortic smooth muscle Intracellular Ca2+ Gap junctions Ca2+-dependent ion currents Dewey 590 44 Département de génétique et évolution 162 false Cell calcium 37 1 e80439a0-451a-4e8c-9357-8222d8194d8a Article (Published version) Restricted M.Fanchaouy.pdf 312174 application/pdf restrictedAccess Faculté des sciences / Section de biologie / Département de génétique et évolution

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Intercellular communication: role of gap junctions in establishing the pattern of ATP-elicited Ca²⁺ oscillations and Ca^2+- dependent currents in freshly isolated aortic smooth muscle cells	Cell calcium			2005	510	1

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Bytchkov, Rostislav