title: Ryanodine as inhibitor of chemotactic peptide-induced chemotaxis in human neutrophils.
abstract: Ryanodine gave a moderate inhibition of chemotactic peptide-activated chemotaxis by intact human neutrophils. Chemotaxis by electroporated neutrophils was strongly inhibited in the nanomolar concentration range. Inhibition of chemotaxis by electroporated neutrophils occurs at concentrations known to open calcium channels in ryanodine-sensitive Ca2+ stores. Whereas migration by formyl-methionyl-leucyl-phenylalanine (fMLP)- or interleukin-8-activated electroporated neutrophils was strongly inhibited by ryanodine, chemotaxis induced by protein kinase C activators was not affected. This suggests that the importance of ryanodine-sensitive Ca2+ stores for migration depends on the type of activator used. Ryanodine gave an increase of cytoplasmic free calcium due to the liberation of calcium from internal stores and to the influx of extracellular calcium. The results show that the neutrophil contains ryanodine-sensitive calcium stores that might be involved in receptor-mediated chemotaxis.
authors.affiliation: Department of Medical Biochemistry, University of Leiden, The Netherlands.
authors.forename: J G
authors.initials: JG
authors.lastname: Elferink
authors.forename: B M
authors.initials: BM
authors.lastname: De Koster
mesh_terms: D002110:Caffeine / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism; D015220:Calcium Channels / Q000187:drug effects; D002465:Cell Movement; D002633:Chemotaxis / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D018274:Electroporation; D006801:Humans; D009240:N-Formylmethionine Leucyl-Phenylalanine / Q000037:antagonists & inhibitors* / Q000494:pharmacology; D009504:Neutrophils / Q000187:drug effects*; D012433:Ryanodine / Q000494:pharmacology*
chemical_list: D015220:Calcium Channels; D012433:Ryanodine; D002110:Caffeine; D009240:N-Formylmethionine Leucyl-Phenylalanine; D002118:Calcium