angiotensin-converting enzyme(redirected from Kininase II)
Also found in: Dictionary, Thesaurus.
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.
Miller-Keane Encyclopedia and Dictionary of Medicine, Nursing, and Allied Health, Seventh Edition. © 2003 by Saunders, an imprint of Elsevier, Inc. All rights reserved.
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
Farlex Partner Medical Dictionary © Farlex 2012
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).
Segen's Medical Dictionary. © 2012 Farlex, Inc. All rights reserved.
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.
McGraw-Hill Concise Dictionary of Modern Medicine. © 2002 by The McGraw-Hill Companies, Inc.
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.
Medical Dictionary for the Health Professions and Nursing © Farlex 2012
angiotensin-converting enzymeThe (ACE) enzyme that converts angiotensin I to the active form angiotensin II. The gene for this enzyme has two alleles, the I allele and the D allele. Research has shown that the I allele is associated with significantly better physical performance, endurance and response to physical training than the D allele. The difference is especially marked if the I allele is present at both loci and compared with people with the D allele at both loci.
Collins Dictionary of Medicine © Robert M. Youngson 2004, 2005