angiotensin-converting enzyme(redirected from Kininase II)
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a vasoconstrictive substance formed in the blood when renin is released from the juxtaglomerular apparatus in the kidney. The enzymatic action of renin acts on angiotensinogen to form the decapeptide angiotensin I, which is relatively inactive. It in turn is acted upon by peptidases (converting enzymes), chiefly in the lungs, to form the octapeptide angiotensin II, a powerful vasopressor and a stimulator of aldosterone secretion by the adrenal cortex. By its vasopressor action, it raises blood pressure and diminishes fluid loss in the kidney by restricting blood flow. Angiotensin II is hydrolyzed in various tissues to form heptapeptide angiotensin III, which has less vasopressor activity but more effect on the adrenal cortex.
angiotensin-converting enzyme (ACE) an enzyme of the hydrolase class that catalyzes cleavage of a dipeptide from the C-terminal end of angiotensin I to form activated angiotensin II; called also peptidyl-dipeptidase A.
angiotensin-converting enzyme inhibitors competitive inhibitors of angiotensin-converting enzyme, which converts angiotensin I to angiotensin II and inactivates bradykinin. ACE inhibitors, such as captopril, are antagonists of the renin-angiotensin-aldosterone system and potentiators of the kinin system and are used for treatment of hypertension, usually in conjunction with a diuretic. They are also used as vasodilators in the treatment of congestive heart failure.
an·gi·o·ten·sin-con·vert·ing en·zyme (ACE),
A zinc-containing hydrolase cleaving C-terminal dipeptides from a variety of substrates, including angiotensin I, which is converted to angiotensin II and histidylleucine (an important step in the metabolism of certain vasopressor agents). Drugs that inhibit it are used to treat hypertension and congestive heart failure.
Synonym(s): peptidyl dipeptidase A
angiotensin-converting enzymePeptidyl-dipeptidase A is the name recommended by the IUBMB for this enzyme (EC 22.214.171.124), though it is more popularly known as angiotensin I-converting enzyme (ACE).
angiotensin-converting enzymeA key enzyme in the RAA system, which converts the inactive decapeptide angiotensin I to the octapeptide, angiotensin II, a potent vasoconstrictor that also stimulates aldosterone secretion; ACE is also involved in metabolizing bradykinin Ref range 18–67 U/L, > age 20; those < 20 have higher levels; ACE is ↑ in sarcoidosis, Gaucher disease, leprosy, histoplasmosis, cirrhosis, asbestosis, berylliosis, DM, Hodgkin's disease, hyperthyroidism, amyloidosis, PBC, idiopathic pulmonary fibrosis, PE, scleroderma, silicosis, TB; ACE ↓ in response to prednisone therapy for sarcoidosis. See Renin/angiotensin/aldosterone system.
an·gi·o·ten·sin-con·vert·ing en·zyme(ACE) (an'jē-ō-ten'sin-kŏn-vĕrt'ing en'zīm)
A hydrolase responsible for the conversion of angiotensin I to the vasoactive angiotensin II by removal of a dipeptide (histidylleucine) from angiotensin I. Drugs that inhibit ACE are used to treat hypertension and congestive heart failure.