title: Time course of platelet alpha granule release in acute myocardial infarction treated with streptokinase.
abstract: OBJECTIVE
  To determine the time course of platelet alpha granule release in patients with acute myocardial infarction treated with streptokinase.
  
  
  METHODS
  A prospective study.
  
  
  METHODS
  Coronary care unit.
  
  
  METHODS
  Nine with myocardial infarction treated with both streptokinase and aspirin, and nine with acute chest pain but without myocardial infarction, who were treated with aspirin only.
  
  
  METHODS
  All patients received 250 mg aspirin on admission and 150 mg once daily thereafter. All patients who fulfilled the indications for streptokinase received 1.5 megaunits, in a single infusion. After the initial medication, serial measurements of plasma beta thromboglobulin and plasma platelet factor 4 were performed at fixed intervals after the onset of chest pain. The primary endpoint sought was the peak value of beta thromboglobulin and platelet factor 4 in each individual.
  
  
  RESULTS
  The median peak plasma beta thromboglobulin in the infarction group was substantially higher than in those without infarction, at 37 (range 12 to 210) v 15 (9 to 36) mg/litre, P < 0.01. The corresponding values for plasma platelet factor 4 were 4.6 (2.4 to 60.0) v 2.2 (< 2 to 8.5) mg/litre, P < 0.01. Increased values were seen only within the first 12 h after onset of chest pain, and after 12 h there was no difference between the patients with myocardial infarction and those without. Aspirin treatment did not abolish alpha granule release.
  
  
  CONCLUSIONS
  In patients with acute myocardial infarction treated with streptokinase the content of the alpha granules is released within the first 12 h after the onset of chest pain. Aspirin apparently does not abolish this release.
authors.affiliation: Mineral metabolic research group, Hvidovre Hospital, University of Copenhagen, Denmark.
authors.forename: N J
authors.initials: NJ
authors.lastname: Frandsen
authors.forename: K
authors.initials: K
authors.lastname: Winther
authors.forename: F
authors.initials: F
authors.lastname: Pedersen
authors.forename: I
authors.initials: I
authors.lastname: Christiansen
authors.forename: P
authors.initials: P
authors.lastname: McNair
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001241:Aspirin / Q000627:therapeutic use; D001792:Blood Platelets / Q000187:drug effects; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000097:blood* / Q000188:drug therapy*; D010978:Platelet Factor 4 / Q000378:metabolism*; D013300:Streptokinase / Q000627:therapeutic use*; D015912:Thrombolytic Therapy; D013997:Time Factors; D001620:beta-Thromboglobulin / Q000378:metabolism*
chemical_list: D001620:beta-Thromboglobulin; D010978:Platelet Factor 4; D013300:Streptokinase; D001241:Aspirin