Intracellular mechanisms involved in leukotriene C4-stimulated adhesion of U-937 cells.
Leukotrienes C4 and D4 (LTC4 and LTD4) stimulated, 5- to 6-fold, the adhesion of the monoblastoid cell line U-937 to plastic. Half-maximal effects were observed around 1 nM. Leukotrienes E4 and B4 (LTE4 and LTB4) were less effective. The adhesive response to LTC4 was inhibited by pertussis toxin and was completely dependent on the presence of extracellular Ca2+. The LTC4-stimulated increases in inositol-phosphates and in intracellular Ca(2+)-concentration were insensitive to pertussis toxin. Activation of leukocyte adhesion is a novel action of cysteinyl-leukotrienes and the present study suggests that control of U-937-cell adhesion by LTC4 involves two pathways; one pertussis toxin insensitive pathway regulating intracellular Ca2+ in a manner partly dependent on extracellular Ca2+ and one pertussis toxin sensitive pathway not concerned with Cai(2+)-regulation.
Skoglund
G
G
Department of Physiological Chemistry, Karolinska Institutet, Stockholm, Sweden.
Claesson
H E
HE
D002118:Calcium / Q000378:metabolism; D002448:Cell Adhesion; D002460:Cell Line; D007295:Inositol Phosphates / Q000378:metabolism; D007962:Leukocytes / Q000502:physiology; D037342:Pertussis Toxin; D013189:SRS-A / Q000502:physiology*; D015398:Signal Transduction; D010566:Virulence Factors, Bordetella / Q000494:pharmacology
D007295:Inositol Phosphates; D013189:SRS-A; D010566:Virulence Factors, Bordetella; D037342:Pertussis Toxin; D002118:Calcium