Endothelium-dependent relaxation in response to poly-L-arginine in canine coronary arteries: implications about hyperpolarization as a mechanism of vasodilatation. Arq Bras Cardiol 2003 Jun;80(6):626-30; 621-5
Date
07/12/2003Pubmed ID
12856072DOI
10.1590/s0066-782x2003000600005Scopus ID
2-s2.0-0141705522 (requires institutional sign-in at Scopus site) 1 CitationAbstract
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 37 C 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 F2 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.
Author List
Evora PR, Pearson PJ, Rodrigues AJ, Viaro F, Schaff HVAuthor
Paul Joseph Pearson MD, PhD Chief, Professor in the Surgery department at Medical College of WisconsinMESH terms used to index this publication - Major topics in bold
AnimalsCoronary Vessels
Dogs
Endothelium, Vascular
Female
Male
Muscle Relaxation
Nitric Oxide
Nitric Oxide Synthase
Peptides
Vasodilation
Vasodilator Agents
