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Predicate | Object |
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rdf:type | |
lifeskim:mentions | |
pubmed:issue |
2
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pubmed:dateCreated |
1988-3-2
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pubmed:abstractText |
Porcine cerebral microvessels were isolated by differential sieving and centrifugation and were characterized by microscopic examination and marker enzyme enrichment (gamma-glutamyltransferase; EC 2.3.2.2). Purified microvessels contained a membrane-bound enzyme immunologically indistinguishable from renal aminopeptidase A (AmA; EC 3.4.11.7). AmA hydrolyzed both alpha-glutamyl- and alpha-aspartyl-2-naphthylamide, and hydrolysis was competitively inhibited by angiotensin II. Micro-vessel AmA hydrolyzed the N-terminal Asp1-Arg2 bond of both angiotensin I and angiotensin II, whereas the angiotensin II antagonist saralasin [(Sar1, Ala8)angiotensin II] was resistant to N-terminal hydrolysis. Angiotensin metabolism was optimal at pH 8.5 and was inhibited by EDTA, o-phenanthroline and amastatin. Conversely, inhibitors of neutral endopeptidase (phosphoramidon), post-proline cleaving enzyme (Z-Pro-Prolinal), carboxypeptidase N [D-L-mercaptomethyl-3-guanidinoethylthiopropanoic acid (MERGETPA)] and angiotensin I converting enzyme (captopril) had no effect. The Km values of angiotensin I, angiotensin II and (Asn1, Val5)angiotensin II for microvessel AmA were 40.1 +/- 8.2, 35.3 +/- 4.3 and 156 +/- 22 microM respectively. Cerebral microvascular aminopeptidase A may play a role in vivo in modulating angiotensin-mediated local cerebral blood flow, and in preventing circulating angiotensins from crossing the blood-brain barrier.
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pubmed:grant | |
pubmed:language |
eng
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pubmed:journal | |
pubmed:citationSubset |
IM
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pubmed:chemical |
http://linkedlifedata.com/resource/pubmed/chemical/Aminopeptidases,
http://linkedlifedata.com/resource/pubmed/chemical/Angiotensin I,
http://linkedlifedata.com/resource/pubmed/chemical/Angiotensin II,
http://linkedlifedata.com/resource/pubmed/chemical/Glutamyl Aminopeptidase,
http://linkedlifedata.com/resource/pubmed/chemical/gamma-Glutamyltransferase
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pubmed:status |
MEDLINE
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pubmed:month |
Jan
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pubmed:issn |
0006-2952
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pubmed:author | |
pubmed:issnType |
Print
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pubmed:day |
15
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pubmed:volume |
37
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
155-60
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pubmed:dateRevised |
2007-11-14
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pubmed:meshHeading |
pubmed-meshheading:2893620-Aminopeptidases,
pubmed-meshheading:2893620-Angiotensin I,
pubmed-meshheading:2893620-Angiotensin II,
pubmed-meshheading:2893620-Animals,
pubmed-meshheading:2893620-Brain,
pubmed-meshheading:2893620-Cerebrovascular Circulation,
pubmed-meshheading:2893620-Glutamyl Aminopeptidase,
pubmed-meshheading:2893620-Kinetics,
pubmed-meshheading:2893620-Microcirculation,
pubmed-meshheading:2893620-Substrate Specificity,
pubmed-meshheading:2893620-Swine,
pubmed-meshheading:2893620-gamma-Glutamyltransferase
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pubmed:year |
1988
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pubmed:articleTitle |
Angiotensin metabolism by cerebral microvascular aminopeptidase A.
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pubmed:affiliation |
Department of Pharmacology, New York Medical College, Valhalla 10595.
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pubmed:publicationType |
Journal Article,
Research Support, U.S. Gov't, P.H.S.
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