The role of the protein C-thrombomodulin system in physiologic anticoagulation during cardiopulmonary bypass.
Changes in the protein C-thrombomodulin (PC-TM) system in relation to other coagulofibrinolytic parameters were examined in 25 patients undergoing open heart surgery. Although all patients were given heparin, a decrease in antithrombin III (ATIII) and progressive increase in thrombin-ATIII complex (TAT) and fibrinopeptide A (FPA) levels were noted during cardiopulmonary bypass, which indicated that heparinization did not completely inhibit the formation of thrombin and its function. C1-inactivator (INA) resistant fibrinolytic activity increased markedly during CPB, in parallel with the change of tissue plasminogen activator antigen (t-PA;Ag), which indicates that fibrinolytic activity during CPB is mainly of extrinsic origin caused by t-PA. Protein C antigen (PC;Ag), protein S antigen (PS;Ag), and thrombomodulin antigen (TM;Ag) were all decreased significantly during CPB. This is considered to reflect the activation and consumption of the PC-TM system in response to generated thrombin. Furthermore, enhancement of the extrinsic fibrinolytic system is easily explained by the action of activated PC, which counteracts plasminogen activator inhibitor (PAI-1), to cause enhancement of t-PA activity.
Tanaka
K
K
Department of Cardiovascular Surgery, Toyo-oka Public Hospital, Hyogo, Japan.
Wada
K
K
Morimoto
T
T
Shomura
S
S
Satoh
T
T
Yada
I
I
Yuasa
H
H
Kusagawa
M
M
Deguchi
K
K
D000328:Adult; D000368:Aged; D001780:Blood Coagulation Tests; D002315:Cardiopulmonary Bypass; D005260:Female; D005342:Fibrinolysis / Q000187:drug effects; D006493:Heparin / Q000008:administration & dosage* / Q000493:pharmacokinetics; D006801:Humans; D008297:Male; D008875:Middle Aged; D011486:Protein C / Q000502:physiology*; D011956:Receptors, Cell Surface / Q000502:physiology*; D018179:Receptors, Thrombin
D011486:Protein C; D011956:Receptors, Cell Surface; D018179:Receptors, Thrombin; D006493:Heparin