Vendrame Stefano, Kristo Aleksandra S, Schuschke Dale A, Klimis-Zacas Dorothy
a Department of Food Science and Human Nutrition, University of Maine, Orono, ME 04469, USA.
Appl Physiol Nutr Metab. 2014 Feb;39(2):255-61. doi: 10.1139/apnm-2013-0249. Epub 2013 Nov 6.
This study evaluates the effect of wild blueberry (WB) consumption on the biomechanical properties of the aorta in the obese Zucker rat (OZR), a model of the metabolic syndrome. Thirty-six OZRs and 36 lean controls (lean Zucker rats) were placed either on a WB-enriched or a control (C) diet for 8 weeks. Phenylephrine (Phe)-mediated vasoconstriction and acetylcholine (Ach)-mediated vasorelaxation in the aortic vessel were investigated, as well as the contribution of the nitric oxide synthase and cyclooxygenase (COX) pathways in each of the above responses by using specific inhibitors. Obese Zucker rats exhibited a reduced vasocontstrictor response to Phe and an exaggerated vasorelaxant response to Ach. The WB diet partially restored Phe-induced constrictor responses and attenuated Ach-induced relaxant responses in OZR. Plasma nitric oxide was significantly attenuated (22.1 ± 1.1 μmol·L(-1), WB vs 25.6 ± 1.4 μmol·L(-1), C, p ≤ 0.05) with the WB diet. Thromboxane A2 levels in the aortic effluent were not significantly affected in the WB diet group, while PGI2 concentration significantly increased (766.5 ± 92.2 pg·mg(-1) aorta in the WB vs 571.7 ± 37.8 pg·g(-1) aorta in the C group, p ≤ 0.05). Downregulation of inducible nitric oxide synthase and COX2 expression in the OZR aorta was observed in the WB diet group. In conclusion, WB consumption altered the biomechanical properties of the OZR aorta by partially restoring the impaired Phe-induced constrictor responses and attenuating the exaggerated response to Ach-induced vasorelaxation.
本研究评估了食用野生蓝莓（WB）对肥胖Zucker大鼠（OZR，一种代谢综合征模型）主动脉生物力学特性的影响。将36只OZR和36只瘦对照（瘦Zucker大鼠）分为富含WB饮食组或对照（C）饮食组，喂养8周。研究了主动脉血管中去氧肾上腺素（Phe）介导的血管收缩和乙酰胆碱（Ach）介导的血管舒张情况，并通过使用特异性抑制剂研究了一氧化氮合酶和环氧化酶（COX）途径在上述每种反应中的作用。肥胖Zucker大鼠对Phe的血管收缩反应降低，对Ach的血管舒张反应增强。WB饮食部分恢复了OZR中Phe诱导的收缩反应，并减弱了Ach诱导的舒张反应。WB饮食使血浆一氧化氮显著降低（WB组为22.1±1.1μmol·L⁻¹，C组为25.6±1.4μmol·L⁻¹，p≤0.05）。WB饮食组主动脉流出液中血栓素A2水平未受到显著影响，而前列环素I2浓度显著升高（WB组主动脉为766.5±92.2pg·mg⁻¹，C组主动脉为571.7±37.8pg·g⁻¹，p≤0.05）。在WB饮食组中观察到OZR主动脉中诱导型一氧化氮合酶和COX2表达下调。总之，食用WB通过部分恢复受损的Phe诱导的收缩反应和减弱对Ach诱导的血管舒张的过度反应，改变了OZR主动脉的生物力学特性。
