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| Predicate | Object |
|---|---|
| rdf:type | |
| lifeskim:mentions | |
| pubmed:dateCreated |
1998-2-5
|
| pubmed:abstractText |
Recent studies have provided evidence of angiotensin converting enzyme (ACE)-independent angiotensin (Ang) II formation in tissue renin-angiotensin systems. We studied the effects of Ang II generated by ACE-independent pathways on renal hemodynamics. We used a synthetic peptide, [Pro11, D-Ala12]-Ang I (S), which yields Ang II by chymase, but not by ACE. Infusion of Ang I into a renal artery caused a decrease in renal blood flow, and reciprocally an increase in mean arterial pressure. Infusion of S (1 nmol/kg) caused a decrease in renal blood flow (-20%), but a larger dose was needed to increase mean arterial pressure. Studies with an intravital needle-probe CCD camera revealed that the Ang I infusion induced dose-dependent vasoconstriction of afferent and efferent arterioles (49% and 54%, respectively at 1 nmol/kg). In contrast, infusion of S elicited only 30% constriction of these vessels at a dose of 1 nmol/kg and induced no further constriction at higher doses, indicating that different segments of renal vessels responded in different fashions to Ang II formed via ACE-independent pathways. These vasoconstrictions were abolished by an angiotensin II receptor (AT-1) antagonist. Enzymatic assays using reverse-phase HPLC revealed that the ACE-dependent pathway was predominant in the rena1 cortex (approximately 80%). We also determined Ang II concentrations in renal cortex specimens obtained by needle biopsy. Intrarenal S infusion (10 nmol/kg) increased plasma and renal Ang II concentrations to 160% and 710% of the respective baseline levels. This study provides in vivo evidence of ACE-independent Ang II formation in renal tissue and suggests that this locally-formed Ang II influences the renal circulation in a paracrine fashion.
|
| pubmed:language |
eng
|
| pubmed:journal | |
| pubmed:citationSubset |
IM
|
| pubmed:chemical | |
| pubmed:status |
MEDLINE
|
| pubmed:month |
Dec
|
| pubmed:issn |
0098-6577
|
| pubmed:author | |
| pubmed:issnType |
Print
|
| pubmed:volume |
63
|
| pubmed:owner |
NLM
|
| pubmed:authorsComplete |
Y
|
| pubmed:pagination |
S132-5
|
| pubmed:dateRevised |
2006-11-15
|
| pubmed:meshHeading | |
| pubmed:year |
1997
|
| pubmed:articleTitle |
Role of angiotensin II generated by angiotensin converting enzyme-independent pathways in canine kidney.
|
| pubmed:affiliation |
Department of Internal Medicine, School of Medicine, Keio University, Tokyo, Japan.
|
| pubmed:publicationType |
Journal Article,
Review,
Research Support, Non-U.S. Gov't
|