ABSTRACT
<p><b>OBJECTIVE</b>To study the effect of tetramethylpyrazine (TMP) on the vascular endothelial cell (VEC) related humoral factors, including endothelin (ET), factor VIII related antigen (i.e. von Willebrand factor, vWF) and thromboxane A2(TXA2) in patients of congenital heart disease with pulmonary hypertension (CHD-PH) during cardiopulmonary bypass (CPB), and explore the clinical physiopathologic significance of them.</p><p><b>METHODS</b>Thirty non-cyanotic patients of CHD-PH were randomly divided into the control group and the treated group. TMP was given to the treated group by intravenous dripping 3 mg/kg after anesthesia induction and adding 1 mg/kg in oxygenator during CPB. Blood samples were collected from radial artery at the time points of after anesthesia induction, 15 min after beginning CPB, 5 min after opening aorta, 20 min, 6 hrs and 24 hrs after stopping CPB, to determine the plasma contents of ET and vWF, as well as TXB2, the stable metabolite of TXA2. The pulmonary vascular reactivity 6 hrs (6h-PVR) after CPB and the mechanical ventilatory support time (VST) after operation were calculated.</p><p><b>RESULTS</b>Levels of ET, vWF and TXB2 increased obviously during CPB, but the degree of increasing in the treated group was lower than that in the control group (P < 0.05), and the 6h-PVR and VST in the former were also lower than those in the latter respectively.</p><p><b>CONCLUSION</b>TMP could obviously reduce the production of ET, vWF and TXB2 during CPB and relieve the pulmonary vascular reactivity after operation, indicating that TMP could reduce the injury of CPB on VEC, and is benefit to enhance the efficacy of treatment.</p>