Changes in cytosolic Ca2+ associated with von Willebrand factor release in human endothelial cells exposed to histamine. Study of microcarrier cell monolayers using …
KK Hamilton, PJ Sims - The Journal of clinical investigation, 1987 - Am Soc Clin Investig
KK Hamilton, PJ Sims
The Journal of clinical investigation, 1987•Am Soc Clin InvestigA method for measuring fluorescence in anchored monolayers of human endothelial cells is
described and used to demonstrate changes in the cytosolic free-calcium concentration
([Ca2+] c) in these cells exposed to histamine and thrombin; some endothelial responses to
both agonists (eg, mitogenesis) have been suggested to be Ca2+-mediated. Umbilical vein
endothelial cells were cultured on microcarriers and loaded with the Ca2+ indicator, indo-1.
Enzymatic cell detachment was avoided by monitoring the indo-1 fluorescence ratio …
described and used to demonstrate changes in the cytosolic free-calcium concentration
([Ca2+] c) in these cells exposed to histamine and thrombin; some endothelial responses to
both agonists (eg, mitogenesis) have been suggested to be Ca2+-mediated. Umbilical vein
endothelial cells were cultured on microcarriers and loaded with the Ca2+ indicator, indo-1.
Enzymatic cell detachment was avoided by monitoring the indo-1 fluorescence ratio …
A method for measuring fluorescence in anchored monolayers of human endothelial cells is described and used to demonstrate changes in the cytosolic free-calcium concentration ([Ca2+]c) in these cells exposed to histamine and thrombin; some endothelial responses to both agonists (e.g., mitogenesis) have been suggested to be Ca2+-mediated. Umbilical vein endothelial cells were cultured on microcarriers and loaded with the Ca2+ indicator, indo-1. Enzymatic cell detachment was avoided by monitoring the indo-1 fluorescence ratio (400/480 nm) of a stirred suspension of cell-covered microcarriers. Basal [Ca2+]c was estimated to be 70-80 nM. Thrombin induced a transient dose-dependent increase in [Ca2+]c, which was active-site dependent. Histamine stimulated a dose-dependent increase in [Ca2+]c, which was reversed by removal of histamine and inhibited competitively by the H1-receptor antagonist pyrilamine, but not by the H2-receptor antagonist cimetidine. Furthermore, histamine induced a dose-dependent secretion of von Willebrand factor, which paralleled the rise in [Ca2+]c and was similarly blocked by the H1-receptor antagonist, and which may contribute to platelet deposition at sites of inflammation.
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