title: The effect of quin2 on chemotaxis by polymorphonuclear leukocytes.
abstract: Exposure of rabbit polymorphonuclear leukocytes to micromolar concentrations of quin2-AM results in high intracellular concentrations of quin2, which lead to inhibition of chemotaxis. The loading efficiency of polymorphonuclear leukocytes, being the percentage of quin2-AM which is taken up by the cells and transformed intracellularly into quin2, is very high, reaches a maximum after 30 min, is independent of the presence of extracellular Ca2+ and is fairly independent of cell concentration. As a consequence, inhibition of chemotaxis is strongly dependent on experimental conditions: with a low cell density (3 X 10(6)/ml) exposure to 20 microM quin2-AM results in complete inhibition of chemotaxis, whereas the same concentration of quin2-AM is nearly without effect when an 8-fold higher cell concentration is used. Inhibition by quin2 is dependent on extracellular Ca2+; inhibition is more pronounced in the absence of extracellular Ca2+ than in its presence. It is suggested that quin2 inhibits chemotaxis by interference with intracellular Ca2+.
mesh_terms: D000255:Adenosine Triphosphate / Q000097:blood; D000634:Aminoquinolines / Q000494:pharmacology*; D000818:Animals; D002465:Cell Movement / Q000187:drug effects; D002634:Chemotaxis, Leukocyte / Q000187:drug effects*; D005456:Fluorescent Dyes / Q000494:pharmacology*; D007700:Kinetics; D009504:Neutrophils / Q000166:cytology / Q000187:drug effects / Q000502:physiology*; D011817:Rabbits
chemical_list: D000634:Aminoquinolines; D005456:Fluorescent Dyes; D000255:Adenosine Triphosphate; C035739:Quin2