Cardiac endothelial cells modulate contractility of rat heart in response to oxygen tension and coronary flow.

摘要: The aim of this study was to determine if endothelial cells in the heart release substances into coronary perfusion medium that modify contractility myocardial cells. To assay effects on cardiac muscle fluid has passed through vasculature, a new method been developed based cascade principle used vascular smooth function. venous effluent from an isolated perfused working collected periodically, and after reoxygenation it as bathing for trabeculae endocardial surface another heart. changed contraction trabeculae. amplitude direction change depended degree oxygen saturation before reoxygenated rate flow at time collected. response trabecula substantially altered by damaging endothelium with 1-second exposure 0.5% Triton X-100 Krebs' solution. It completely eliminated both producing which assayed. Therefore, are required presence cardioactive effluent. production labile endothelium-derived upregulating (positively inotropic) factor more stable downregulating (negatively demonstrated appears account all changes produced Neither is nitric oxide or endothelin. concentration sensitive tension, whereas but not tension. contain stimulate secretion (preendothelial factors) well have (endothelial factors). results indicate during passage vasculature factors added perfusate relative concentrations depend least part local tissue PO2 flow. In intact heart, mechanism could operate maintain balance between energy supply work performed.