Carbon monoxide releasing molecule-2 improves protamine-mediated hypocoagulation/hyperfibrinolysis in human plasma in vitro.
BACKGROUND
Protamine sulfate has been implicated as a possible cause of coagulopathy for over 20 y. Protamine has been demonstrated to decrease thrombin activity and to prolong bleeding. We tested the hypothesis that a new hemostatic agent, carbon monoxide releasing molecule-2 (tricarbonyldichlororuthenium (II) dimer; CORM-2), could attenuate protamine-mediated hypocoagulation/hyperfibrinolysis in plasma.


METHODS
Normal plasma was exposed to 0, 12.5, 25, or 50 μg/mL of protamine, with or without addition of 100 μM CORM-2. Tissue factor was used to initiate coagulation, and tissue type plasminogen activator was added in some experiments. Additional experiments were performed wherein plasma was exposed to protamine combined with 0% or 30% dilution with normal saline, with or without CORM-2 addition. Thrombelastography was performed until either stable clot strength or clot lysis occurred.


RESULTS
Protamine, in a concentration-dependent fashion, significantly prolonged the onset of coagulation, decreased the velocity of thrombus growth, and decreased clot strength in the absence or presence of tissue type plasminogen activator. Further, protamine significantly decreased the time to onset of fibrinolysis and decreased clot lysis time. CORM-2 exposure significantly diminished all aforementioned protamine-mediated effects on coagulation and fibrinolysis. Lastly, CORM-2 addition significantly increased the velocity of clot growth and strength in diluted, protamine-exposed plasma.


CONCLUSIONS
CORM-2 attenuated protamine-mediated hypocoagulation/hyperfibrinolysis at clinically encountered concentrations. Additional preclinical investigation is warranted to determine if CORM-2 administration will be efficacious in diminishing coagulopathy caused by protamine.
Department of Anesthesiology, Drexel University College of Medicine, Philadelphia, Pennsylvania 19102, USA. vance.nielsen@drexelmed.edu
Vance G
VG
Nielsen
S Nini
SN
Malayaman
Jack B
JB
Cohen
Joshua M
JM
Persaud
D001777:Blood Coagulation / Q000187:drug effects*; D006438:Hemodilution; D006494:Heparin Antagonists / Q000494:pharmacology*; D006801:Humans; D009942:Organometallic Compounds / Q000494:pharmacology*; D011479:Protamines / Q000494:pharmacology*; D013916:Thrombelastography; D010959:Tissue Plasminogen Activator
D006494:Heparin Antagonists; D009942:Organometallic Compounds; D011479:Protamines; C447082:tricarbonyldichlororuthenium (II) dimer; D010959:Tissue Plasminogen Activator