endothelial dysfunction

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Original Article

Effect of Pitavastatin on Vascular Reactivity in Hypercholesterolemic Rabbits

Eros Antonio de Almeida et al. Michiko Regina Ozaki

Background:

Pitavastatin is the newest statin available in Brazil and likely the one with fewer side effects. Thus, pitavastatin was evaluated in hypercholesterolemic rabbits in relation to its action on vascular reactivity.

Objective:

To assess the lowest dose of pitavastatin necessary to reduce plasma lipids, cholesterol and tissue lipid peroxidation, as well as endothelial function in hypercholesterolemic rabbits.

Methods:

Thirty rabbits divided into six groups (n = 5): G1 – standard chow diet; G2 – hypercholesterolemic diet for 30 days; G3 – hypercholesterolemic diet and after the 16th day, diet supplemented with pitavastatin (0.1 mg); G4 – hypercholesterolemic diet supplemented with pitavastatin (0.25 mg); G5 – hypercholesterolemic diet supplemented with pitavastatin (0.5 mg); G6 – hypercholesterolemic diet supplemented with pitavastatin (1.0 mg). After 30 days, total cholesterol, HDL, triglycerides, glucose, creatine kinase (CK), aspartate aminotransferase (AST), alanine aminotransferase (ALT) were measured and LDL was calculated. In-depth anesthesia was performed with sodium thiopental and aortic segments were removed to study endothelial function, cholesterol and tissue lipid peroxidation. The significance level for statistical tests was 5%.

Results:

Total cholesterol and LDL were significantly elevated in relation to G1. HDL was significantly reduced in G4, G5 and G6 when compared to G2. Triglycerides, CK, AST, ALT, cholesterol and tissue lipid peroxidation showed no statistical difference between G2 and G3-G6. Significantly endothelial dysfunction reversion was observed in G5 and G6 when compared to G2.

Conclusion:

Pitavastatin starting at a 0.5 mg dose was effective in reverting endothelial dysfunction in hypercholesterolemic rabbits.

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Artigo Original

Resistive exercise in the evaluation of endothelial dysfunction in heart failure

Ricardo Tavares de Carvalho et al. Marcelo Luis Campos Vieira Ângela Romano Liliane Kopel Silvia G. Lage

OBJECTIVE: To evaluate the use of resistive exercise in the study of endothelial dysfunction in heart failure (HF) comparatively to reactive hyperemia (RH). METHODS: Eighteen patients with heart failure and 15 normal volunteers were submitted to intermittent handgrip exercise in a pneumatic bag, at an intensity that corresponds to 75% of the previously assessed maximum load. Patients underwent high-resolution vascular ultrasonography for brachial artery diameter and flow evaluation as well as cardiac output determination at rest, RH and after exercise. The systolic flow index in the brachial artery and cardiac index were calculated. RESULTS: Systolic flow index increase in the brachial artery was observed after RH and physical exercise, with the latter presenting the highest increase. There was an increase in the cardiac index after the study conditions in comparison to resting conditions. CONCLUSION: Resistive exercise, performed at the assessed load, increases blood flow more intensively than RH, constituting a physiological option for the evaluation of endothelial function in HF.

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Original Article

Effects of high glucose concentrations on the endothelial function of the renal microcirculation of rabbits

Filipe de Souza Affonso et al. Solange Cailleaux Leonardo Felipe Corrêa Pinto Marília de Brito Gomes Eduardo Tibiriçá

OBJECTIVE: To assess the acute effects of high glucose concentrations on vascular reactivity in the isolated non diabetic rabbit kidney. METHODS: Rabbits were anaesthetized for isolation of the kidneys. Renal arteries and veins were cannulated for perfusion with Krebs-Henselleit solution and measurement of perfusion pressure. After 3 hours of perfusion with glucose 5,5 mM (control ) and 15 mM, the circulation was submitted to sub maximal precontraction (80% of maximal response) trough continuous infusion of noradrenaline 10 mM. Vascular reactivity was then assessed trough dose-responses curves with endothelium-dependent (acetylcholine) and independent (sodium nitroprusside) vasodilators. The influence of hyperosmolarity was analyzed with perfusion with mannitol 15mM. RESULTS: A significant reduction in the endothelium-dependent vasodilation in glucose 15mM group was observed compared to that in control, but there was no difference in endothelium-independent vasodilation. After perfusion with mannitol 15 mM, a less expressive reduction in endothelium-dependent vasodilation was observed, only reaching significance in regard to the greatest dose of acetylcholine. CONCLUSION: High levels of glucose similar to those found in diabetic patients in the postprandial period can cause significant acute changes in renal vascular reactivity rabbits. In diabetic patients these effects may also occur and contribute to diabetes vascular disease.

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Effect of Pitavastatin on Vascular Reactivity in Hypercholesterolemic Rabbits

Background:

Objective:

Methods:

Results:

Conclusion:

Resistive exercise in the evaluation of endothelial dysfunction in heart failure

Effects of high glucose concentrations on the endothelial function of the renal microcirculation of rabbits

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Electronic Document Format (Vancouver)

Electronic Document Format (ABNT)

Electronic Document Format (APA)

Electronic Document Format (ISO)

Electronic Document Format (Vancouver)

Electronic Document Format (ABNT)

Electronic Document Format (APA)

Electronic Document Format (ISO)