Endothelium-dependent relaxation in response to poly-L-arginine in canine coronary arteries: implications about hyperpolarization as a mechanism of vasodilatation
OBJECTIVE: To study the mechanism by which poly-L-arginine mediates endothelium-dependent relaxation. METHODS: Vascular segments with and without endothelium were suspended in organ chambers filled with control solution maintained at 37ºC and bubbled with 95% O2 / 5% CO2. Used drugs: indomethacin, a...
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| Format: | Article |
| Language: | English |
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Sociedade Brasileira de Cardiologia (SBC)
2003-06-01
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| Series: | Arquivos Brasileiros de Cardiologia |
| Subjects: | |
| Online Access: | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0066-782X2003000600005 |
| _version_ | 1818845450754588672 |
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| author | Paulo R. B. Evora Paul J. Pearson Alfredo José Rodrigues Fernanda Viaro Hartzell V. Schaff |
| author_facet | Paulo R. B. Evora Paul J. Pearson Alfredo José Rodrigues Fernanda Viaro Hartzell V. Schaff |
| author_sort | Paulo R. B. Evora |
| collection | DOAJ |
| description | OBJECTIVE: To study the mechanism by which poly-L-arginine mediates endothelium-dependent relaxation. METHODS: Vascular segments with and without endothelium were suspended in organ chambers filled with control solution maintained at 37ºC and bubbled with 95% O2 / 5% CO2. Used drugs: indomethacin, acetycholine, EGTA, glybenclamide, ouabain, poly-L-arginine, methylene blue, N G-nitro-L-arginine, and verapamil and N G-monomethyl-L-arginine. Prostaglandin F2á and potassium chloride were used to contract the vascular rings. RESULTS: Poly-L-arginine (10-11 to 10-7 M) induced concentration-dependent relaxation in coronary artery segments with endothelium. The relaxation to poly-L-arginine was attenuated by ouabain, but was unaffected by glybenclamide. L-NOARG and oxyhemoglobin caused attenuation, but did not abolish this relaxation. Also, the relaxations was unaffected by methylene blue, verapamil, or the presence of a calcium-free bathing medium. The endothelium-dependent to poly-L-arginine relaxation was abolished only in vessels contracted with potassium chloride (40 mM) in the presence of L-NOARG and indomethacin. CONCLUSION: These experiments indicate that poly-L-arginine induces relaxation independent of nitric oxide. |
| first_indexed | 2024-12-19T05:29:51Z |
| format | Article |
| id | doaj.art-7a5b83b316fc4397a25ab10cc2b611fd |
| institution | Directory Open Access Journal |
| issn | 0066-782X 1678-4170 |
| language | English |
| last_indexed | 2024-12-19T05:29:51Z |
| publishDate | 2003-06-01 |
| publisher | Sociedade Brasileira de Cardiologia (SBC) |
| record_format | Article |
| series | Arquivos Brasileiros de Cardiologia |
| spelling | doaj.art-7a5b83b316fc4397a25ab10cc2b611fd2022-12-21T20:34:16ZengSociedade Brasileira de Cardiologia (SBC)Arquivos Brasileiros de Cardiologia0066-782X1678-41702003-06-0180662663010.1590/S0066-782X2003000600005Endothelium-dependent relaxation in response to poly-L-arginine in canine coronary arteries: implications about hyperpolarization as a mechanism of vasodilatationPaulo R. B. EvoraPaul J. PearsonAlfredo José RodriguesFernanda ViaroHartzell V. SchaffOBJECTIVE: To study the mechanism by which poly-L-arginine mediates endothelium-dependent relaxation. METHODS: Vascular segments with and without endothelium were suspended in organ chambers filled with control solution maintained at 37ºC and bubbled with 95% O2 / 5% CO2. Used drugs: indomethacin, acetycholine, EGTA, glybenclamide, ouabain, poly-L-arginine, methylene blue, N G-nitro-L-arginine, and verapamil and N G-monomethyl-L-arginine. Prostaglandin F2á and potassium chloride were used to contract the vascular rings. RESULTS: Poly-L-arginine (10-11 to 10-7 M) induced concentration-dependent relaxation in coronary artery segments with endothelium. The relaxation to poly-L-arginine was attenuated by ouabain, but was unaffected by glybenclamide. L-NOARG and oxyhemoglobin caused attenuation, but did not abolish this relaxation. Also, the relaxations was unaffected by methylene blue, verapamil, or the presence of a calcium-free bathing medium. The endothelium-dependent to poly-L-arginine relaxation was abolished only in vessels contracted with potassium chloride (40 mM) in the presence of L-NOARG and indomethacin. CONCLUSION: These experiments indicate that poly-L-arginine induces relaxation independent of nitric oxide.http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0066-782X2003000600005poly-L-argininepolycationsnitric oxideEDHFendothelium |
| spellingShingle | Paulo R. B. Evora Paul J. Pearson Alfredo José Rodrigues Fernanda Viaro Hartzell V. Schaff Endothelium-dependent relaxation in response to poly-L-arginine in canine coronary arteries: implications about hyperpolarization as a mechanism of vasodilatation Arquivos Brasileiros de Cardiologia poly-L-arginine polycations nitric oxide EDHF endothelium |
| title | Endothelium-dependent relaxation in response to poly-L-arginine in canine coronary arteries: implications about hyperpolarization as a mechanism of vasodilatation |
| title_full | Endothelium-dependent relaxation in response to poly-L-arginine in canine coronary arteries: implications about hyperpolarization as a mechanism of vasodilatation |
| title_fullStr | Endothelium-dependent relaxation in response to poly-L-arginine in canine coronary arteries: implications about hyperpolarization as a mechanism of vasodilatation |
| title_full_unstemmed | Endothelium-dependent relaxation in response to poly-L-arginine in canine coronary arteries: implications about hyperpolarization as a mechanism of vasodilatation |
| title_short | Endothelium-dependent relaxation in response to poly-L-arginine in canine coronary arteries: implications about hyperpolarization as a mechanism of vasodilatation |
| title_sort | endothelium dependent relaxation in response to poly l arginine in canine coronary arteries implications about hyperpolarization as a mechanism of vasodilatation |
| topic | poly-L-arginine polycations nitric oxide EDHF endothelium |
| url | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0066-782X2003000600005 |
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