title: Migration of human granulocytes in filters: effects of gravity and movable gradients of f-MLP.
abstract: The Boyden chamber technique for chemotaxis uses a mesh filter that constitutes a matrix for cell locomotion and, at the same time, creates a local restriction for convective fluid movements that allows the establishment of a diffusive concentration gradient of chemotactic substance in the filter. In the present study, the Boyden chamber was modified by the introduction of a filter sandwich that allowed cell migration both upwards and downwards and by the use of a fluid density gradient controlling cell buoyancy and mechanically supporting a movable chemotactic gradient. This method was used to study chemotaxis and random migration of human granulocytes under the influence of gravitational forces and movable gradients of f-MLP. The results show that gravity affected cell motion significantly during random migration but not during chemotaxis. The rate of chemotactic migration was dependent on the steepness of the spatio-temporal f-MLP gradients. A stationary spatial gradient produced less migration than a gradient that was slowly moved through the filter sandwich in a direction opposite to that of the cell migration. The presence of f-MLP at constant concentration caused a minor, statistically insignificant, increase of the rate of random migration.
authors.affiliation: Department of Anatomy, University of Göteborg, Sweden.
authors.forename: M
authors.initials: M
authors.lastname: Braide
authors.forename: P R
authors.initials: PR
authors.lastname: Ebrahimzadeh
authors.forename: K G
authors.initials: KG
authors.lastname: Strid
authors.forename: L M
authors.initials: LM
authors.lastname: Bjursten
mesh_terms: D002465:Cell Movement / Q000502:physiology; D002634:Chemotaxis, Leukocyte; D003198:Computer Simulation; D006098:Granulocytes / Q000502:physiology*; D006112:Gravitation; D006440:Hemofiltration; D006801:Humans; D008954:Models, Biological