Dependence of neutrophil activation on cell density and adhesion.
Upon an increasing cell density human neutrophils develop more cell-to-cell contacts in conjunction with an increase in the pHi. These changes are accompanied by decreased superoxide formation after adherence, and a decrease in the total amount of 5-lipoxygenase products after various stimuli. Among the various arachidonate metabolites, leukotriene formation remained almost constant but the yield in 5-HETE decreased. This drop in could account for the decrease in total 5-lipoxygenase products observed when the cell density increased. We conclude that cellular signalling can be affected by an increase of cell-cell interactions. Whether the increase in cellular pH is a cause or consequence of such contact inhibition has yet be answered.
Sud'ina
G F
GF
A.N. Belozersky Institute of Physico-Chemical Biology, Moscow State University, Russia. sudina@bk408.genebee.msu.su
Galkina
S I
SI
Margolis
L B
LB
Ullrich
V
V
D001094:Arachidonate 5-Lipoxygenase / Q000378:metabolism; D016718:Arachidonic Acid / Q000378:metabolism*; D000001:Calcimycin / Q000494:pharmacology; D002118:Calcium / Q000502:physiology; D002448:Cell Adhesion; D002452:Cell Count; D002478:Cells, Cultured; D004357:Drug Synergism; D006801:Humans; D006863:Hydrogen-Ion Concentration; D006893:Hydroxyeicosatetraenoic Acids / Q000096:biosynthesis; D007476:Ionophores / Q000494:pharmacology; D007975:Leukotriene B4 / Q000096:biosynthesis*; D009240:N-Formylmethionine Leucyl-Phenylalanine / Q000494:pharmacology; D009504:Neutrophils / Q000166:cytology / Q000187:drug effects / Q000502:physiology*; D017382:Reactive Oxygen Species / Q000378:metabolism; D016897:Respiratory Burst; D015398:Signal Transduction / Q000502:physiology; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology
D006893:Hydroxyeicosatetraenoic Acids; D007476:Ionophores; D017382:Reactive Oxygen Species; D007975:Leukotriene B4; D016718:Arachidonic Acid; D000001:Calcimycin; C022022:5-hydroxy-6,8,11,14-eicosatetraenoic acid; D009240:N-Formylmethionine Leucyl-Phenylalanine; D001094:Arachidonate 5-Lipoxygenase; D013755:Tetradecanoylphorbol Acetate; D002118:Calcium