Relaxamento dependente do endotélio causado pela Poli-L-Arginia. Implicações sobre a hiperpolarizaçäo como mecanismo de vasodilataçäo / Endothelium-dependent relaxation in response to poly-L-arginine in canine coronary arteries: implications about hyperpolarization as a mechanism of vasodilatation
Arq. bras. cardiol
; 80(6): 626-630, Jun. 2003. tab, graf
Article
in Pt, En
| LILACS
| ID: lil-339137
Responsible library:
BR1.1
ABSTRACT
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 percent O2 / 5 percent 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
Full text:
1
Index:
LILACS
Main subject:
Peptides
/
In Vitro Techniques
/
Endothelium, Vascular
/
Coronary Vessels
/
Muscle Relaxation
/
Nitric Oxide
Limits:
Animals
Language:
En
/
Pt
Journal:
Arq. bras. cardiol
Journal subject:
CARDIOLOGIA
Year:
2003
Type:
Article