Intercellular calcium signaling in procine aortic smooth muscle cells

• Main Authors: hsu chiu chi, 許秋琪
• Other Authors: SHEAU-HUEI CHUEH
• Format: Others
• Language: zh-TW
• Published: 2000
• Online Access: http://ndltd.ncl.edu.tw/handle/60298097825020827641

碩士 === 國防醫學院 === 生物化學研究所 === 88 === ABSTRACT In cultured porcine aortic smooth muscle cells, ejection of 30 μM ATP to a single cell, a rapid increase of cytosolic Ca2+ concentration [Ca2+]i was seen and this Ca2+ signal would be propagated from the stimulated cell to the neighboring cells which have not been exposed to ATP. The spreading of Ca2+ signal occurred from 2 to 8 sec. In contrast, Ca2+ wave propagation among cells was not seen following stimulation of cells with 10 μM sphingosylphosphorylcholine (SPC), 10 μM thapsigargin (TG), or 155 mM K+. Global exposure of cells to ATP, SPC, TG or high K+ in the culture dish, [Ca2+]i increases were seen in all cells. ATP-induced Ca2+ wave propagation was not seen after intracellular Ca2+ pools had been depleted by TG or phospholopase C inhibited by U73122, while it remained the same following removal of extracellular Ca2+. Pretreatment of cells with AGA, to block gap junction, AACOCF3 and HELSS, to block phospholipase A2, ADMA, to block nitric oxide synthase, ODQ, to block guanylyl cyclase, staurosporine, to block protein kinases, indomethacin, to block cyclooxygenase, and carboxy-PTIO, to scavenge nitric oxide, all had no effect on ATP-induced Ca2+ wave propagation. Furthermore, ATP-induced Ca2+ propagation is not inhibited by pretreatment of cells with proton ionophore, FCCP or CCCP. Our results indicate that the propagation of Ca2+ signal induced by ATP in porcine aortic smooth muscle cells depends on the fullness of intracellular Ca2+ pools and the generation of IP3, is not mediated by the generation of arachidonic acid and its downstream metabolites, NO, or cGMP, and is independent to extracellular Ca2+, mitochondrial Ca2+ or protein phosphorylation. To confirm whether the Ca2+ wave propagation requires the involvement of gap junction and the secretion of receptor agonist needs further studies.