  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==  thumb|150px|left|anatomical diagram of the renin-angiotensin system, showing the role of ace at the lungs.page 866-867 (integration of salt and water balance) and 1059 (the adrenal gland) in:   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,{{cite journal | author = imig jd | title = ace inhibition and bradykinin-mediated renal vascular responses: edhf involvement | journal = hyperten
EC_3.4.15 Human_proteins Kininakallikrein_system Peptidase