ABSTRACT
The effects of normothermic or hypothermic cardiopulmonary bypass(CPB)on hemodynamics, plasma levels of endothelin(ET)and atrial natriuetic peptide(ANP)were comparatively studied in dogs with Swan-Ganz catheter technique and radioimmunoassay. The results showed the total peripheral resistance(TPR)during hypothermic CPB was significantly higher than that of the normothermic. Plasm ET levels increased significantly during hypothermic CPB but remained stable during normothermic CPB. Plasma ANP levels almost unchanged during either CPB. Plasma ET level was positively correlated to TPR but ANT level was not. The results suggest that the increased ET levels may be one of the causes of higher TPR during hypothermic CPB;the stable ET levels contributes to the maintenance of cardiovascular function during and after normothermic CPB and the ANP amount secreted beyond the heart has little effect on the plasma level and hemodynamics during CPB.