Circadian variations in natural coagulation inhibitors protein C, protein S and antithrombin in healthy men: A possible association with interleukin-6

Undar L., Ertugrul C., Altunbas H., Akca S.

THROMBOSIS AND HAEMOSTASIS, vol.81, no.4, pp.571-575, 1999 (SCI-Expanded) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 81 Issue: 4
  • Publication Date: 1999
  • Doi Number: 10.1055/s-0037-1614526
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.571-575
  • Akdeniz University Affiliated: No


Recent observations describe an increase in platelet aggregability and a decrease in fibrinolytic activity in the early morning hours. To determine whether anticoagulant proteins also show such a circadian variation we measured protein C (PC), protein S (PS), antithrombin (AT) and heparin cofactor-II (HC-II) levels on venous plasma samples taken from 10 healthy men at three-hour intervals throughout a 24-hour period. To investigate the possible temporal mapping of circadian periodicity, we also measured plasma levels of beta-thromboglobulin (beta-TG) as an indicator of platelet activation, and interleukin-6 (IL-6) as one of the possible regulatory factors that drive this rhythm.