血管内皮细胞中细胞钙的动态数字荧光率影像(英文)

Dynamic digital fluorescence ratio imaging of cell calcium in vascular endothelial cells

AIM: To study the spatial and temporal distribution of intracellular Ca2+ concentration in cultured bovine pulmonary artery endothelial ( BPAE ) cells. METHODS: Cultured BPAE cells were loaded with Fura-2 and observed under an inverted microscope coupled to a microfluorimeter, which enables pixel-to-pixel ratio imaging of the BPAE cells in real time. RESULTS: Addition of Ca2+ 1-2 mmol·L-1 to BPAE cells, which were exposed to Ca2 + -fiee medium containing egtazic acid, resulted in a transient elevation of cytosolic Ca2+ concentration, which rapidly returned to the resting level. Biphasic elevation (a larger transient phase followed by a smaller sustained phase) of intracellular Ca2+ concentration was observed upon the addition of ATP (via activation of surface membrane receptor). 4-Chloro-3-ethyl phenol (CEP; an activator of Ca2+-induced Ca2+ channels) potently induced elevation of Ca2+ level. Cyclopiazonic acid (CPA; an inhibitor of endoplasmic reticulum Ca2+-ATPase pump) offered a more sustained

AIM: To study the spatial and temporal distribution of intracellular Ca2+ concentration in cultured bovine pulmonary artery endothelial ( BPAE ) cells. METHODS: Cultured BPAE cells were loaded with Fura-2 and observed under an inverted microscope coupled to a microfluorimeter, which enables pixel-to-pixel ratio imaging of the BPAE cells in real time. RESULTS: Addition of Ca2+ 1-2 mmol·L-1 to BPAE cells, which were exposed to Ca2 + -fiee medium containing egtazic acid, resulted in a transient elevation of cytosolic Ca2+ concentration, which rapidly returned to the resting level. Biphasic elevation (a larger transient phase followed by a smaller sustained phase) of intracellular Ca2+ concentration was observed upon the addition of ATP (via activation of surface membrane receptor). 4-Chloro-3-ethyl phenol (CEP; an activator of Ca2+-induced Ca2+ channels) potently induced elevation of Ca2+ level. Cyclopiazonic acid (CPA; an inhibitor of endoplasmic reticulum Ca2+-ATPase pump) offered a more sustained elevation of Ca2+ . In most cases, the highest level of Ca2+ elevation was observed around the cell peripheries, sometimes at rest and particularly upon stimulation. Ca2+ elevation associated with nuclear complex seemed to be higher compared to that in the cytosolic compartment. CONCLUSION: Changes of cell Ca2+upon stimulation by various agents that acted at diiferent intracellular sites were found to be temporarily and spatially heterogeneous among BPAE cells. At the single cell level, Ca2+ elevation seemed to occur initially near the peripheral region followed by the nuclear region. This study raised the possibility that nuclear Ca2+ and cytosolic Ca2+ might be regulated independently in BPAE cells.