Platelet adhesion at low shear rate: Study of a normal population

• Published in: Thrombosis research Vol. 69; no. 2; pp. 173 - 184
• Main Authors: Dores, Graça M., Miller, Marilyn E., Thorpe, Susan L.
• Format: Journal Article
• Language: English
• Published: New York, NY Elsevier Ltd 15.01.1993; Elsevier Science
• Subjects: Adult; Aspirin - pharmacology; Biological and medical sciences; Blood coagulation. Blood cells; Collagen - pharmacology; Contraceptives, Oral - pharmacology; estrogen replacement therapy; Female; Fibronectins - pharmacology; Fundamental and applied biological sciences. Psychology; Humans; Male; Menopause; Menstruation; Middle Aged; Molecular and cellular biology; oral contraceptives; Platelet; platelet adhesion; Platelet Adhesiveness - drug effects; Platelet Adhesiveness - physiology; Platelet Count; Population; Reference Values; Regional Blood Flow - physiology; Thrombosis - etiology; oral contraceptives; estrogen replacement therapy; platelet adhesion; Human; Hormone; Platelet; Contraceptive; Adhesion; Estrogen; Hemic System; Estrogens > administraction and dosage; Laboratory Examinations And Diagnoses; Oral Contraceptives > side effects; Risk Factors; Biology; Contraception; Hormones; Laboratory Procedures; Contraceptive Methods > side effects; Family Planning; Examinations And Diagnoses; Thrombosis; Embolism; Endocrine System; Diseases; Platelet Aggregation; Hematological Effects; Vascular Diseases; Physiology; Thromboembolism
• ISSN: 0049-3848; 1879-2472
• DOI: 10.1016/0049-3848(93)90043-N

The use of oral contraceptives (OCs) has been associated with vascular complications. The mechanism(s) by which OCs predispose to thrombotic events remains unclear. Recent studies have demonstrated that postmenopausal (PM) women who take estrogen replacement therapy (ERT) have a decreased incidence of myocardial infarction compared to those who do not take ERT. This study was undertaken to determine if healthy individuals have differences in platelet adhesion depending on hormonal status. Men, PM women taking ERT, PM women not taking ERT, OC users, and premenopausal women not taking any medications were studied. Platelet studies were performed in a Hele-Shaw flow chamber at a low shear rate using platelet-rich plasma. The platelet adhesion process to subendothelial components: fibronectin, collagen I and collagen III was recorded using a 35 mm camera mounted on an inverted microscope. Photographs were taken at 30 second intervals for a total of 12 minutes and analyzed using a modified computer program which provided a numerical account of platelet adhesion. OC users had significantly higher platelet adherence to fibronectin, collagen I and collagen III compared to all other groups. All other study groups had similar platelet adhesion independent of hormonal status. These findings suggest that OCs cause increased platelet adhesion in some individuals and this may be one of the mechanisms by which OCs contribute to thrombotic events.