OBJECTIVES: The aim was to test a newly discovered oligopeptide, pENW (pGlu-Asn-Trp), for its anticoagulant and antithrombotic activity in vivo, and try to investigate its underlying mechanisms. METHODS: We measured coagulation time by the glass slide method and bleeding time by cutting of mice tails. The thrombosis models employed here included an arterio-venous shunt model and inferior vena ligation model. An ELISA (enzyme-linked immunosorbent assay) was used to analyse t-PA/PAI (tissue-type plasminogen activator/plasminogen activator inhibitor) in the blood drawn from the rats with thrombosis. The ultrastructural changes of the endothelium in the vessels developing thrombosis were observed under a transmission electron microscope. KEY FINDINGS: We found that pENW-treated mice exhibited a prolonged coagulation time in a dose-dependent manner, but not an extended haemorrhage time. On the other hand, pENW significantly inhibited thrombus formation in both arterio-venous shunt models and inferior vena ligation models. Plasma t-PA/PAI was significantly higher as measured by ELISA. Transmission electron microscope photos of pENW-treated groups also displayed a better condition than model controls, with less erythrocytes in the vascular lumens. In addition, pENW concentration-dependently inhibited aggregation of platelets induced by ADP (adenosine 5'-diphosphate sodium salt) in rabbit platelet-rich plasma. CONCLUSIONS: These findings support the suggestion that pENW possesses antithrombotic activity and could be a promising drug in the prevention and treatment of unwanted clot formation.
OBJECTIVES: The aim was to test a newly discovered oligopeptide, pENW (pGlu-Asn-Trp), for its anticoagulant and antithrombotic activity in vivo, and try to investigate its underlying mechanisms. METHODS: We measured coagulation time by the glass slide method and bleeding time by cutting of mice tails. The thrombosis models employed here included an arterio-venous shunt model and inferior vena ligation model. An ELISA (enzyme-linked immunosorbent assay) was used to analyse t-PA/PAI (tissue-type plasminogen activator/plasminogen activator inhibitor) in the blood drawn from the rats with thrombosis. The ultrastructural changes of the endothelium in the vessels developing thrombosis were observed under a transmission electron microscope. KEY FINDINGS: We found that pENW-treated mice exhibited a prolonged coagulation time in a dose-dependent manner, but not an extended haemorrhage time. On the other hand, pENW significantly inhibited thrombus formation in both arterio-venous shunt models and inferior vena ligation models. Plasma t-PA/PAI was significantly higher as measured by ELISA. Transmission electron microscope photos of pENW-treated groups also displayed a better condition than model controls, with less erythrocytes in the vascular lumens. In addition, pENW concentration-dependently inhibited aggregation of platelets induced by ADP (adenosine 5'-diphosphate sodium salt) in rabbit platelet-rich plasma. CONCLUSIONS: These findings support the suggestion that pENW possesses antithrombotic activity and could be a promising drug in the prevention and treatment of unwanted clot formation.