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Celotto,A.C.; Capellini,V.K.; Baldo,C.F.; Dalio,M.B.; Rodrigues,A.J.; Evora,P.R.B.. |
Acid-base homeostasis maintains systemic arterial pH within a narrow range. Whereas the normal range of pH for clinical laboratories is 7.35-7.45, in vivo pH is maintained within a much narrower range. In clinical and experimental settings, blood pH can vary in response to respiratory or renal impairment. This altered pH promotes changes in vascular smooth muscle tone with impact on circulation and blood pressure control. Changes in pH can be divided into those occurring in the extracellular space (pHo) and those occurring within the intracellular space (pHi), although, extracellular and intracellular compartments influence each other. Consistent with the multiple events involved in the changes in tone produced by altered pHo, including type of vascular... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Acid-base balance; Nitric oxide; Vascular reactivity; Endothelium; Alkalosis; Acidosis. |
Ano: 2008 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2008000600001 |
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Discigil,B.; Evora,P.R.B.; Pearson,P.J.; Viaro,F.; Rodrigues,A.J.; Schaff,H.V.. |
To determine if radiocontrast impairs vascular relaxation of the renal artery, segments (4-5 mm in length) of canine renal artery were suspended in vitro in organ chambers to measure isometric force (95% O2/5% CO2, at 37ºC). Arterial segments with and without endothelium were placed at the optimal point of their length-tension relation and incubated with 10 µM indomethacin to prevent synthesis of endogenous prostanoids. The presence of nonionic radiocontrast (iohexol, Omnipaque 350, 1 ml in 25 ml control solution, 4% (v/v)) did not alter endothelium-dependent relaxation to acetylcholine in rings precontracted with both norepinephrine and prostaglandin F2alpha (N = 6). When the rings were precontracted with prostaglandin F2alpha, the presence of ionic... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Radiocontrast; Renal failure; Nitric oxide; Vasodilation. |
Ano: 2004 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2004000200014 |
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Rodrigues,A.J.; Évora,P.R.B.; Schaff,H.V.. |
The present study investigated the protective effect of N-acetylcysteine (NAC) against oxygen radical-mediated coronary artery injury. Vascular contraction and relaxation were determined in canine coronary arteries immersed in Kreb's solution (95% O2-5% CO2), incubated or not with NAC (10 mM), and exposed to free radicals (FR) generated by xanthine oxidase (100 mU/ml) plus xanthine (0.1 mM). Rings not exposed to FR or NAC were used as controls. The arteries were contracted with 2.5 µM prostaglandin F2alpha. Subsequently, concentration-response curves for acetylcholine, calcium ionophore and sodium fluoride were obtained in the presence of 20 µM indomethacin. Concentration-response curves for bradykinin, calcium ionophore, sodium nitroprusside, and... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Coronary arteries; N-acetylcysteine; Endothelium; Oxidative stress; Nitric oxide. |
Ano: 2004 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2004000800012 |
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