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- Publisher Website: 10.1152/ajpheart.00289.2007
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- PMID: 17557920
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Article: Increased spontaneous tone in renal arteries of spontaneously hypertensive rats
Title | Increased spontaneous tone in renal arteries of spontaneously hypertensive rats |
---|---|
Authors | |
Keywords | Cyclooxygenase Large-conductance calcium-activated potassium channels Nitric oxide |
Issue Date | 2007 |
Publisher | American Physiological Society. The Journal's web site is located at http://intl-ajpheart.physiology.org/ |
Citation | American Journal Of Physiology - Heart And Circulatory Physiology, 2007, v. 293 n. 3, p. H1673-H1681 How to Cite? |
Abstract | The spontaneous tone of vascular smooth muscle is augmented in hypertension. The present study examined the role of nitric oxide (NO), cyclooxygenase (COX), thromboxane A2/prostanoid (TP) and PGE 2/prostanoid (EP-1) receptors, reactive oxygen species, and large-conductance Ca2+-activated K+ (BKCa) channels in the regulation of spontaneous tone in renal arteries of young and mature Wistar-Kyoto (WKY) and spontaneously hypertensive rats (SHR). Rings of arteries, with and without endothelium, were suspended in a myograph for isometric force recording. Spontaneous tone (increase above initial tension) was observed only in arteries of mature SHR and was greater in arteries without endothelium. Nω-nitro-L-arginine methyl ester (L-NAME, an inhibitor of NO synthases) induced larger contractions in arteries of SHR than WKY. Indomethacin (a COX inhibitor), SC-19220 (an EP-1 receptor antagonist), and terutroban (a TP receptor antagonist) reduced the L-NAME-evoked contractions. Tiron (a superoxide anion scavenger), catalase (an enzyme that degrades H 2O2), and deferoxamine (a hydroxyl radical scavenger) augmented the L-NAME-induced contractions in arteries of mature SHR. Charybdotoxin (a BKCa channel blocker) caused contractions in arteries of mature SHR without endothelium and in arteries with endothelium incubated with L-NAME. A decreased protein level of endothelial NO synthase, an increased release of prostacyclin, and an increased expression of EP-1 receptors were observed in arteries of mature SHR. The present study suggests that spontaneous tone is precipitated by age and hypertension. The reduced production of NO, leading to decreased activation of BKCa channels, may leave the actions of endogenous vasoconstrictors unopposed. COX products that activate EP-1 and TP receptors are involved in the development of spontaneous tone. Copyright © 2007 the American Physiological Society. |
Persistent Identifier | http://hdl.handle.net/10722/171358 |
ISSN | 2023 Impact Factor: 4.1 2023 SCImago Journal Rankings: 1.452 |
ISI Accession Number ID | |
References |
DC Field | Value | Language |
---|---|---|
dc.contributor.author | Michel, FS | en_US |
dc.contributor.author | Man, RYK | en_US |
dc.contributor.author | Vanhoutte, PM | en_US |
dc.date.accessioned | 2012-10-30T06:13:35Z | - |
dc.date.available | 2012-10-30T06:13:35Z | - |
dc.date.issued | 2007 | en_US |
dc.identifier.citation | American Journal Of Physiology - Heart And Circulatory Physiology, 2007, v. 293 n. 3, p. H1673-H1681 | en_US |
dc.identifier.issn | 0363-6135 | en_US |
dc.identifier.uri | http://hdl.handle.net/10722/171358 | - |
dc.description.abstract | The spontaneous tone of vascular smooth muscle is augmented in hypertension. The present study examined the role of nitric oxide (NO), cyclooxygenase (COX), thromboxane A2/prostanoid (TP) and PGE 2/prostanoid (EP-1) receptors, reactive oxygen species, and large-conductance Ca2+-activated K+ (BKCa) channels in the regulation of spontaneous tone in renal arteries of young and mature Wistar-Kyoto (WKY) and spontaneously hypertensive rats (SHR). Rings of arteries, with and without endothelium, were suspended in a myograph for isometric force recording. Spontaneous tone (increase above initial tension) was observed only in arteries of mature SHR and was greater in arteries without endothelium. Nω-nitro-L-arginine methyl ester (L-NAME, an inhibitor of NO synthases) induced larger contractions in arteries of SHR than WKY. Indomethacin (a COX inhibitor), SC-19220 (an EP-1 receptor antagonist), and terutroban (a TP receptor antagonist) reduced the L-NAME-evoked contractions. Tiron (a superoxide anion scavenger), catalase (an enzyme that degrades H 2O2), and deferoxamine (a hydroxyl radical scavenger) augmented the L-NAME-induced contractions in arteries of mature SHR. Charybdotoxin (a BKCa channel blocker) caused contractions in arteries of mature SHR without endothelium and in arteries with endothelium incubated with L-NAME. A decreased protein level of endothelial NO synthase, an increased release of prostacyclin, and an increased expression of EP-1 receptors were observed in arteries of mature SHR. The present study suggests that spontaneous tone is precipitated by age and hypertension. The reduced production of NO, leading to decreased activation of BKCa channels, may leave the actions of endogenous vasoconstrictors unopposed. COX products that activate EP-1 and TP receptors are involved in the development of spontaneous tone. Copyright © 2007 the American Physiological Society. | en_US |
dc.language | eng | en_US |
dc.publisher | American Physiological Society. The Journal's web site is located at http://intl-ajpheart.physiology.org/ | en_US |
dc.relation.ispartof | American Journal of Physiology - Heart and Circulatory Physiology | en_US |
dc.subject | Cyclooxygenase | - |
dc.subject | Large-conductance calcium-activated potassium channels | - |
dc.subject | Nitric oxide | - |
dc.subject.mesh | Animals | en_US |
dc.subject.mesh | Disease Models, Animal | en_US |
dc.subject.mesh | Endothelium, Vascular - Physiopathology | en_US |
dc.subject.mesh | Hypertension - Physiopathology | en_US |
dc.subject.mesh | Male | en_US |
dc.subject.mesh | Muscle Hypertonia - Physiopathology | en_US |
dc.subject.mesh | Nitric Oxide - Physiology | en_US |
dc.subject.mesh | Potassium Channels - Physiology | en_US |
dc.subject.mesh | Prostaglandin-Endoperoxide Synthases - Physiology | en_US |
dc.subject.mesh | Prostaglandins - Metabolism | en_US |
dc.subject.mesh | Rats | en_US |
dc.subject.mesh | Rats, Inbred Shr | en_US |
dc.subject.mesh | Rats, Inbred Wky | en_US |
dc.subject.mesh | Receptors, Prostaglandin E - Physiology | en_US |
dc.subject.mesh | Receptors, Prostaglandin E, Ep1 Subtype | en_US |
dc.subject.mesh | Receptors, Thromboxane A2, Prostaglandin H2 - Physiology | en_US |
dc.subject.mesh | Renal Artery - Physiopathology | en_US |
dc.title | Increased spontaneous tone in renal arteries of spontaneously hypertensive rats | en_US |
dc.type | Article | en_US |
dc.identifier.email | Man, RYK:rykman@hkucc.hku.hk | en_US |
dc.identifier.email | Vanhoutte, PM:vanhoutt@hku.hk | en_US |
dc.identifier.authority | Man, RYK=rp00236 | en_US |
dc.identifier.authority | Vanhoutte, PM=rp00238 | en_US |
dc.description.nature | link_to_subscribed_fulltext | en_US |
dc.identifier.doi | 10.1152/ajpheart.00289.2007 | en_US |
dc.identifier.pmid | 17557920 | - |
dc.identifier.scopus | eid_2-s2.0-34548396787 | en_US |
dc.relation.references | http://www.scopus.com/mlt/select.url?eid=2-s2.0-34548396787&selection=ref&src=s&origin=recordpage | en_US |
dc.identifier.volume | 293 | en_US |
dc.identifier.issue | 3 | en_US |
dc.identifier.spage | H1673 | en_US |
dc.identifier.epage | H1681 | en_US |
dc.identifier.isi | WOS:000249237800045 | - |
dc.publisher.place | United States | en_US |
dc.identifier.scopusauthorid | Michel, FS=7402556401 | en_US |
dc.identifier.scopusauthorid | Man, RYK=7004986435 | en_US |
dc.identifier.scopusauthorid | Vanhoutte, PM=7202304247 | en_US |
dc.identifier.issnl | 0363-6135 | - |