title: A plasmatic factor may cause platelet activation in acute ischemic stroke.
abstract: To study the pathogenesis of platelet activation in ischemic stroke, ionized calcium ([Cai2+]) was measured in aequorin-loaded gel-filtered platelets in the basal and stimulated state. Basal [Cai2+] was increased in stroke patients maximally 36-72 hours after onset. The increase in [Cai2+] after stimulation with thrombin, collagen, and platelet-activating factor were also greater in stroke patients, but the profiles of these [Cai2+] changes were parallel to control. Cross incubation of control platelets with plasma from stroke patients resulted in raised basal [Cai2+] and caused the release of serotonin from platelets. These results indicate that the higher platelet basal [Cai2+] in stroke patients represents a lowered threshold for activation and that this may be due to a plasmatic factor rather than a primary platelet defect.
authors.affiliation: Department of Neurology, Henry Ford Hospital, Detroit, Michigan.
authors.forename: R
authors.initials: R
authors.lastname: Joseph
authors.forename: K M
authors.initials: KM
authors.lastname: Welch
authors.forename: S B
authors.initials: SB
authors.lastname: Oster
authors.forename: S
authors.initials: S
authors.lastname: Grunfeld
authors.forename: G
authors.initials: G
authors.lastname: D'Andrea
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D001792:Blood Platelets / Q000502:physiology*; D002118:Calcium / Q000097:blood; D002561:Cerebrovascular Disorders / Q000097:blood*; D003094:Collagen / Q000494:pharmacology; D006801:Humans; D066298:In Vitro Techniques; D008875:Middle Aged; D015539:Platelet Activation; D012701:Serotonin / Q000378:metabolism; D012737:Sex Factors
chemical_list: D012701:Serotonin; D003094:Collagen; D002118:Calcium