title: Role of nitric oxide on in vitro human eosinophil migration.
abstract: Eosinophils purified from the rat peritoneal cavity have been found to contain nitric oxide synthase (NOS) functionally coupled to a cyclic GMP transduction pathway that is involved in in vitro eosinophil migration, but no studies on cell locomotion have been done with purified human eosinophils. Therefore, this study was carried out to investigate the effects of N(omega) -nitro-L-arginine methyl ester (L-NAME; a non-selective NOS inhibitor), 1-(2-trifluoromethylphenyl) imidazole (TRIM; a type I/type II NOS inhibitor), 2-amino-5,6-dihydro-6-methyl-4H-1,3-thiazine (AMT; a selective type II NOS inhibitor), and 1H-[1,2,4]-oxidiazolo[4,3-a] quinoxalin-1-one (ODQ; a soluble guanylate cyclase inhibitor) on human eosinophil migration induced by N-formyl-methionyl-leucyl-phenylalanine (fMLP). Human eosinophils were purified from peripheral blood of healthy volunteers using a Percoll gradient followed by an immunomagnetic cell separator. Chemotaxis was evaluated using a 48-well microchemotaxis chamber. The fMLP (1.0 x 10(-7) M)-induced eosinophil migration was reduced significantly by l-NAME (0.1 and 1.0 mM), whereas the inactive enantiomer N(omega)-nitro-D-arginine methyl ester (D-NAME) had no effect. The inhibition by l-NAME was restored by sodium nitroprusside (0.25 mM). The NOS inhibitors AMT and TRIM (0.05 to 0.25 mM each) also markedly attenuated fMLP-induced chemotaxis. Additionally, ODQ (0.01 to 0.5 mM) concentration-dependently inhibited fMLP-induced migration, and the inhibition was restored by 2.0 mM dibutyryl cyclic GMP. In conclusion, this study demonstrates that human eosinophils present a nitric oxide-cyclic GMP pathway that is involved in the in vitro locomotion of this cell type.
authors.affiliation: Department of Pharmacology, Faculty of Medical Sciences, UNICAMP, P.O. Box 6111, 13081-970, (SP), Campinas, Brazil.
authors.forename: S M
authors.initials: SM
authors.lastname: Thomazzi
authors.forename: H H
authors.initials: HH
authors.lastname: Ferreira
authors.forename: N
authors.initials: N
authors.lastname: Conran
authors.forename: G
authors.initials: G
authors.lastname: De Nucci
authors.forename: E
authors.initials: E
authors.lastname: Antunes
mesh_terms: D002465:Cell Movement / Q000187:drug effects / Q000502:physiology*; D002633:Chemotaxis / Q000187:drug effects; D004347:Drug Interactions; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004804:Eosinophils / Q000166:cytology* / Q000187:drug effects / Q000201:enzymology; D006162:Guanylate Cyclase / Q000037:antagonists & inhibitors / Q000378:metabolism; D006801:Humans; D007093:Imidazoles / Q000494:pharmacology; D009240:N-Formylmethionine Leucyl-Phenylalanine / Q000494:pharmacology; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology; D009569:Nitric Oxide / Q000502:physiology*; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors / Q000378:metabolism; D010069:Oxadiazoles / Q000494:pharmacology; D011810:Quinoxalines / Q000494:pharmacology
chemical_list: C095284:1H-(1,2,4)oxadiazolo(4,3-a)quinoxalin-1-one; D004791:Enzyme Inhibitors; D007093:Imidazoles; D010069:Oxadiazoles; D011810:Quinoxalines; C098186:1-(2-trifluoromethylphenyl)imidazole; D009569:Nitric Oxide; D009240:N-Formylmethionine Leucyl-Phenylalanine; D019001:Nitric Oxide Synthase; D006162:Guanylate Cyclase; D019331:NG-Nitroarginine Methyl Ester