<n0:ComplexDefinition xmlns:n0="http://ncicb.nci.nih.gov/xml/owl/EVS/ComplexProperties.xsd#"><n0:def-definition>A prodrug and non-sulfhydryl angiotensin converting enzyme (ACE) inhibitor with antihypertensive activity. Quinapril is hydrolized into its active form quinaprilat, which binds to and inhibits ACE, thereby blocking the conversion of angiotensin I to angiotensin II. This abolishes the potent vasoconstrictive actions of angiotensin II and leads to vasodilatation. Quinapril also causes a decrease in angiotensin II-induced aldosterone secretion by the adrenal cortex, thereby promoting diuresis and natriuresis, and increases bradykinin levels.</n0:def-definition><n0:def-source>NCI</n0:def-source></n0:ComplexDefinition>