system
Medical AI Inquiry: You was designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.  Labels: BACKGROUND. Meshes: Aortic Valve Stenosis, Cardiomyopathy, Dilated, Enzyme Activation, Fluorescent Antibody Technique, Heart Failure, Heart Ventricles, Humans, Microscopy, Fluorescence, Myocardium, Neprilysin, RNA, Messenger, Transcriptional Activation.
user
Is neutral endopeptidase activated in cardiomyocytes in human aortic valve stenosis and heart failure? Context: The regulation of the cardiac neutral endopeptidase (EC 24.10, NEP) that degrades bradykinin and natriuretic peptides has been investigated in human cardiac hypertrophy and heart failure. Methods and Results- NEP mRNA was quantitated by real-time polymerase chain reaction (PCR) in left ventricular biopsies from patients with aortic valve stenosis (AS, n=19) and heart failure due to dilated cardiomyopathy (DCM, n=14), and control subjects with normal systolic function (CON, n=14). Left ventricular NEP mRNA content was increased 3-fold in AS (P<0.005) and 4.1-fold in DCM (P<0.002). The increase in NEP mRNA was related to the increase in end diastolic pressure in AS and DCM. In a second series, myocardial NEP enzymatic activity was determined. It increased 3.6-fold in AS (P<0.02) and 4-fold in DCM (P<0.002). NEP was localized in the myocardium by immunofluorescence microscopy and in situ PCR to myocytes and nonmyocyte areas and cells.
assistant
Elevated cardiac NEP activity in pressure loaded and failing human hearts may increase the local degradation of bradykinin and natriuretic peptides. Final Decision: yes