title: Platelet-induced granulocyte aggregation in vitro.
abstract: Recent studies have shown that the response of granulocytes to stimulation is increased by the presence of platelets. Using an assay based on counting aggregates with a Coulter Counter, we found that heparinized or citrated platelet-rich plasma directly caused aggregation of isolated granulocytes. Platelets themselves were frequently present within the granulocyte aggregates. The degree of aggregation depended on the platelet:granulocyte ratio, and increased over a 2--5 min period of mixing, with a slower increase thereafter. Aggregation was calcium-dependent, increased by stimulation of the platelets with ADP or collagen but not serotonin, and only slightly reduced by a thrombin inhibitor (hirudin, at concentrations up to 0.9 U/ml). A similar adhesive interaction in vivo might be relevant to thrombotic and ischaemic pathology.
authors.affiliation: Department of Haematology, Medical School, Birmingham, UK.
authors.forename: T
authors.initials: T
authors.lastname: Maeda
authors.forename: G B
authors.initials: GB
authors.lastname: Nash
authors.forename: B
authors.initials: B
authors.lastname: Christopher
authors.forename: Z
authors.initials: Z
authors.lastname: Pecsvarady
authors.forename: J A
authors.initials: JA
authors.lastname: Dormandy
mesh_terms: D001792:Blood Platelets / Q000502:physiology*; D002118:Calcium / Q000494:pharmacology*; D002449:Cell Aggregation / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D006098:Granulocytes / Q000187:drug effects / Q000502:physiology*; D006801:Humans
chemical_list: D002118:Calcium