| Enhanced myogenic response in the afferent arteriole of spontaneously hypertensive rats. | |
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MedLine Citation:
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PMID: 20363886 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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Spontaneously hypertensive rats (SHRs) have normal glomerular capillary pressure even though renal perfusion pressure is higher, suggesting that preglomerular vessels exhibit abnormally high resistance. This may be due to increased superoxide (O(2)(-)) production, which contributes to the vasoconstriction in hypertension. We tested the hypothesis that the myogenic response of the afferent arteriole (Af-Art) is exaggerated in SHRs because of increased levels of reactive oxygen species (ROS). Single Af-Arts were microdissected from kidneys of SHRs and Wistar-Kyoto (WKY) rats and microperfused in vitro. When perfusion pressure in the Af-Art was increased stepwise from 60 to 140 mmHg, the luminal diameter decreased by 8.4 + or - 2.9% in WKY Af-Arts but fell by 29.3 + or - 5.6% in SHR Af-Arts. To test whether ROS production is enhanced during myogenic response in SHRs, we measured chloromethyl-dichlorodihydrofluorescein diacetate acetyl ester (CM-H(2)DCFDA) florescence before and after increasing intraluminal pressure from 60 to 140 mmHg. Pressure-induced increases in ROS were fourfold greater in SHR Af-Arts compared with WKY Af-Arts (SHR, 48.0 + or - 2.2%; and WKY, 12.2 + or - 0.3%). To test whether O(2)(-) contributes to the myogenic response in SHRs, either the membrane-permeant O(2)(-) scavenger Tempol or the nox2-based NADPH oxidase (NOX2) inhibitor gp91ds-tat were added to the Af-Art lumen and bath and the myogenic response was tested before and after treatment. Both Tempol (10(-4) M) and gp91ds-tat (10(-5) M) significantly attenuated the pressure-induced constriction in SHR Af-Arts but not in WKY Af-Arts. We conclude that 1) pressure-induced constriction is exaggerated in SHR Af-Arts, 2) NOX2-derived O(2)(-) may contribute to the enhanced myogenic response, and 3) O(2)(-) exerts little influence on the myogenic response under normotensive conditions. |
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Authors:
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YiLin Ren; Martin A D'Ambrosio; Ruisheng Liu; Patrick J Pagano; Jeffrey L Garvin; Oscar A Carretero |
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Publication Detail:
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Type: Comparative Study; Journal Article; Research Support, N.I.H., Extramural; Research Support, Non-U.S. Gov't Date: 2010-04-02 |
Journal Detail:
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Title: American journal of physiology. Heart and circulatory physiology Volume: 298 ISSN: 1522-1539 ISO Abbreviation: Am. J. Physiol. Heart Circ. Physiol. Publication Date: 2010 Jun |
Date Detail:
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Created Date: 2010-05-20 Completed Date: 2010-06-23 Revised Date: 2011-07-28 |
Medline Journal Info:
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Nlm Unique ID: 100901228 Medline TA: Am J Physiol Heart Circ Physiol Country: United States |
Other Details:
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Languages: eng Pagination: H1769-75 Citation Subset: IM |
Affiliation:
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Hypertension and Vascular Research Division, Dept. of Internal Medicine, Henry Ford Hospital, 2799 W. Grand Blvd., Detroit, MI 48202, USA. yren1@hfhs.org |
Export Citation:
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| MeSH Terms | |
Descriptor/Qualifier:
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Animals Antioxidants / pharmacology Arterioles / physiology* Blood Pressure / physiology Cyclic N-Oxides / pharmacology Disease Models, Animal Hypertension / physiopathology* Kidney / blood supply* Male Membrane Glycoproteins / metabolism Muscle, Smooth, Vascular / physiology* NADPH Oxidase / metabolism Rats Rats, Inbred SHR Rats, Inbred WKY Reactive Oxygen Species / metabolism Regional Blood Flow / physiology Spin Labels Superoxides / metabolism Vasoconstriction / drug effects, physiology* |
| Grant Support | |
ID/Acronym/Agency:
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HL-28982/HL/NHLBI NIH HHS; P01 HL028982-29/HL/NHLBI NIH HHS; R01 HL088036-04/HL/NHLBI NIH HHS |
| Chemical | |
Reg. No./Substance:
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0/Antioxidants; 0/Cyclic N-Oxides; 0/Membrane Glycoproteins; 0/Reactive Oxygen Species; 0/Spin Labels; 11062-77-4/Superoxides; 2226-96-2/tempol; EC 1.6.-/Cybb protein, rat; EC 1.6.3.1/NADPH Oxidase |
| Comments/Corrections | |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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