Histamine-induced calcium oscillations in human vascular smooth muscle: temporal sequence and spatial organization in single cells.
1. Video imaging of single, fura2-loaded vascular smooth muscle cells was used to examine the spatial and temporal alterations in calcium, Ca2+, in response to low levels of vasoconstrictor stimuli. 2. Histamine (0.5 mumol/L) produced repetitive oscillations in Ca2+, which appeared to show some variation in amplitude and frequency between cells. 3. Individual oscillations consisted of an initial increase in Ca2+ in a localized region followed by a wave-like propagation of this region of elevated Ca2+ throughout the rest of the cell cytoplasm. 4. It is suggested that the subcellular spatial organization of Ca2+ that was observed during a Ca2+ oscillation allows a population of cells to operate in unison. Thus, oscillatory fluctuations in Ca2+ may contribute to myogenic tone.
Neylon
C B
CB
Department of Biochemistry, AFRC Institute of Animal Physiology & Genetics Research, Babraham, Cambridge, United Kingdom.
Mason
W T
WT
Irvine
R F
RF
D002118:Calcium / Q000378:metabolism*; D002478:Cells, Cultured; D003593:Cytoplasm / Q000378:metabolism; D005260:Female; D006632:Histamine / Q000494:pharmacology*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007424:Intracellular Fluid / Q000378:metabolism; D008853:Microscopy / Q000379:methods; D009131:Muscle, Smooth, Vascular / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D014471:Umbilical Veins / Q000166:cytology / Q000187:drug effects / Q000378:metabolism
D006632:Histamine; D002118:Calcium