Expression of XXXX , endothelin-converting enzyme, and endothelin receptors in @entity712 .

@entity1 @entity712 @entity2232 @entity17614 @entity384 @entity299 @entity2231
BACKGROUND: Elevated plasma levels of @entity2232 have been reported in association with @entity299 , including @entity712 . Furthermore, it has been suggested that ET-1 acts as a local autocrine/paracrine factor with biological activities such as vasoconstriction, mitogenesis, and inotropic effects on the heart. This study investigated alterations of ET-1, ET receptor, and endothelin-converting enzyme ( @entity17614 ) expression in left ventricular myocardium from @entity1 with end-stage @entity712 . METHODS AND RESULTS: mRNA concentrations of @entity2231 and ETB receptors, @entity2232 ( @entity2232 ), and @entity17614 in left ventricles from nonfailing donors hearts (NF) and from @entity1 with end-stage @entity712 (NYHA functional class IV) due to @entity384 ( @entity384 ) were compared by use of a competitive reverse transcription-polymerase chain reaction technique. There was no significant difference in mRNA expression for @entity2232 , @entity17614 , and @entity2231 receptors, whereas a significant reduction of ETB-receptor mRNA was observed in @entity384 hearts. 125I-labeled ET-1 radioligand binding studies demonstrated a significant downregulation of ETB receptors, whereas @entity2231 -receptor density was increased in membranes from @entity384 hearts. Phosphoramidon-sensitive @entity17614 activity and immunodetectable amounts of @entity17614 protein in left ventricular membrane preparations did not differ between NF and @entity384 hearts. Finally, immunoreactive ET-1 concentrations were increased in @entity384 hearts. CONCLUSIONS: The present study demonstrates changes in the ET-receptor expression pattern in favor of the @entity2231 receptor in @entity1 end-stage @entity712 . Furthermore, activation of the cardiac ET system with increased tissue ET-1 concentrations in the failing myocardium is observed. This is more likely due to decreased clearance than to increased synthesis, because @entity2232 gene expression and @entity17614 activity are unchanged.
