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Angiotensin-converting enzyme (), or "ACE" indirectly increases blood pressure by causing blood vessels to constrict. It does that by converting angiotensin I to angiotensin II, which constricts the vessels. For this reason, drugs known as ACE inhibitors are used to lower blood pressure. ACE is also known by the following names: ''dipeptidyl carboxypeptidase I'', ''peptidase P'', ''dipeptide hydrolase'', ''peptidyl dipeptidase'', ''angiotensin converting enzyme'', ''kininase II'', ''angiotensin I-converting enzyme'', ''carboxycathepsin'', ''dipeptidyl carboxypeptidase'', "hypertensin converting enzyme" ''peptidyl dipeptidase I'', ''peptidyl-dipeptide hydrolase'', ''peptidyldipeptide hydrolase'', ''endothelial cell peptidyl dipeptidase'', ''peptidyl dipeptidase-4'', ''PDH'', ''peptidyl dipeptide hydrolase'', and ''DCP''. ACE, angiotensin I and angiotensin II are part of the renin-angiotensin system (RAS), which controls blood pressure by regulating the volume of fluids in the body. ACE is secreted in the lungs and kidneys by cells in the endothelium (inner layer) of blood vessels. ==Functions== It has two primary functions: * ACE catalyses the conversion of angiotensin I to angiotensin II, a potent vasoconstrictor in a substrate concentration-dependent manner. * ACE degrades bradykinin, a potent vasodilator, and other vasoactive peptides. These two actions make ACE inhibition a goal in the treatment of conditions such as high blood pressure, heart failure, diabetic nephropathy, and type 2 diabetes mellitus. Inhibition of ACE (by ACE inhibitors) results in the decreased formation of angiotensin II and decreased metabolism of bradykinin, leading to systematic dilation of the arteries and veins and a decrease in arterial blood pressure. In addition, inhibiting angiotensin II formation diminishes angiotensin II-mediated aldosterone secretion from the adrenal cortex, leading to a decrease in water and sodium reabsorption and a reduction in extracellular volume. Kininase II is the same as angiotensin-converting enzyme. Thus, the same enzyme (ACE) that generates a vasoconstrictor (ANG II) also disposes of vasodilators (bradykinin).〔Boron and Boulpaed Medical Physiology 2nd edition Updated〕 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Angiotensin-converting enzyme」の詳細全文を読む スポンサード リンク
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