This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pathology
[{'content': 'Brain natriuretic peptide is degraded by \nSelect and explain. \nA. Neutral endopeptidase, B. Elastase, C. Collagenase, D. Ompatrilat', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Brain natriuretic peptide or B type natriuretic peptide: It is a hormone produced by the ventricles of the heart.\nIt has been shown to increase in response to ventricular volume expansion and pressure overload. B.N.P. is a marker of ventricular systolic and diastolic function.\nLike Atrial natriuretic peptide, it is degraded by neutral endopeptidase. Atrial natriuretic peptide:\nAtrial natriuretic factor (ANP) is a hormone released by atrial walls of the heart when they become stretched.\nBecause in heart failure,\nthere is an almost always excessive increase in both the right and left atrial pressures that stretch the atrial walls the circulating levels of ANP in the blood increase\nfivefold to tenfold in severe heart failure. The ANF, in turn, has a direct effect on the kidneys to increase greatly their excretion of salt and water.\nTherefore ANP plays a natural role to prevent the extreme congestive symptoms of cardiac failure.\nBut the other factors promoting cardiac decompensation quickly overrides this ANP effect.\nMore on the physiological properties of ANP: Circulating ANP has a short half-life.\nTheir steady level in blood is maintained by clearance receptors. It is metabolized by neutral endopeptidase (NEP) which is inhibited by Thiorphan.', 'role': 'assistant'}]