Different distribution of two types of angiotensin II-generating enzymes in the aortic wall.
Dog, monkey and human aortic tissues contained two distinct types of angiotensin II-generating enzymes; angiotensin converting enzyme (ACE) and chymostatin-sensitive angiotensin II-generating enzyme (CAGE). Endothelium, media and adventitia of canine thoracic aortae were separated using collagenase digestion, and determined for their ACE and CAGE activity. ACE activity was assayed by hippuryl-His-Leu cleavage. CAGE activity was estimated with ANG I as substrate in the presence of inhibitors of ACE and angiotensinases. His-Leu, the common product of both enzyme reactions, was fluorimetrically quantified after o-phthalaldehyde condensation. ACE localized mainly in endothelium, while CAGE distributed predominantly in adventitia. Similar results were obtained with human and monkey aortae. Such a contrasting distribution may indicate the distinct functional role of these two enzymes.
Okunishi
H
H
Department of Pharmacology, Shiga University of Medical Science, Otsu, Japan.
Miyazaki
M
M
Okamura
T
T
Toda
N
N
D001011:Aorta / Q000201:enzymology* / Q000648:ultrastructure; D003238:Connective Tissue / Q000201:enzymology; D004547:Elastic Tissue / Q000201:enzymology; D010450:Endopeptidases / Q000494:pharmacology; D004730:Endothelium, Vascular / Q000201:enzymology; D009842:Oligopeptides / Q000378:metabolism / Q000494:pharmacology; D007703:Peptidyl-Dipeptidase A / Q000032:analysis*; D012697:Serine Endopeptidases / Q000032:analysis*; D015842:Serine Proteinase Inhibitors
D009842:Oligopeptides; D015842:Serine Proteinase Inhibitors; C010980:hippuryl-histidyl-leucine; C002101:chymostatin; D010450:Endopeptidases; D007703:Peptidyl-Dipeptidase A; D012697:Serine Endopeptidases; C054542:chymostatin-sensitive angiotensin II-generating enzyme