Wild blueberry-rich diets affect the contractile machinery of the vascular smooth muscle in the Sprague-Dawley rat.
J MED FOOD
8 - 13.
Weanling male Sprague-Dawley rats were randomly fed a control diet (AIN-93) (C) or a blueberry diet (B) for 13 weeks, or a reverse diet (R) (C diet for 13 weeks, switched to the B diet for 8 weeks). Aortas were excised, and two intact and two endothelium-denuded rings were immersed in tissue baths containing physiological salt solution at 37 degrees C and aerated with 95% O-2, and 5% CO2 (pH 7.4), Following equilibration and preconditioning under 1.5-g preload, cumulative dose-response curves were generated with six doses of the alpha 1-adrenergic receptor-selective agonist L-phenylephrine (L-Phe, 10(-8)-3 X 10(-6) M) and relaxed with one dose of acetylcholine (3 X 10(-6) M) to assess intact endothelium. The maximum force of contraction (F-max) and vessel sensitivity (pD(2)) were determined in intact and endothelium-denuded rings. A two-way analysis of variance test revealed that blueberry-fed animals (B and R diets) developed a significantly lower F,,,,, (0.873 +/- 0.0463 and 0.9266 +/- 0.0463 a, respectively) when contracted with L-Phe, compared with the animals on the C diet (1.109 +/- 0.0463 g) (P < .05). The pD(2) of the intact rings was not significantly different among diet groups. Additionally, diet did not significantly affect the mean or pD(2) of endothelium-denuded rings. Our results indicate for the first time that wild blueberries incorporated into the diet affect the vascular smooth muscle contractile machinery by suppressing the alpha 1-adrenergic receptor agonist-mediated contraction while having no effect on membrane sensitivity of the endothelial or vascular smooth muscle cell layer. Furthermore, their mechanism of action seems to be accomplished through ail endothelium-dependent pathway.
|Title:||Wild blueberry-rich diets affect the contractile machinery of the vascular smooth muscle in the Sprague-Dawley rat|
|Keywords:||blueberries, contractile properties, diet, vascular smooth muscle, ENDOTHELIUM-DEPENDENT VASORELAXATION, SERUM ANTIOXIDANT STATUS, NITRIC-OXIDE PRODUCTION, CARDIOVASCULAR-DISEASE, OXIDATIVE STRESS, BLOOD-VESSELS, AORTA, ANTHOCYANINS, INCREASES, POLYPHENOLS|
|UCL classification:||UCL > School of Life and Medical Sciences
UCL > School of Life and Medical Sciences > Faculty of Medical Sciences
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