Food Science and Human Nutrition, University of Maine , Orono, ME , USA .
Int J Food Sci Nutr. 2013 Dec;64(8):979-87. doi: 10.3109/09637486.2013.825698. Epub 2013 Aug 15.
The role of wild blueberries (WB) on key signaling steps of nitric oxide (NO) and cyclooxygenase (COX) pathways was examined in spontaneously hypertensive rats (SHRs) after eight weeks on a control (C) or an 8% w/w WB diet. Aortic rings from SHRs were stimulated with phenylephrine (Phe) in the absence or presence of inhibitors of: soluble guanylyl cyclase (sGC), phosphodiesterase-5 (PDE(5)), prostaglandin I(2) (PGI(2)) synthase and thromboxane A(2) (TXA(2)) synthase. Additionally, enzymatic activities in these pathways were determined by the concentration of NO, cyclic guanosine monophosphate (cGMP), PGI(2) and TXA(2). In the WB-fed SHR, attenuation of Phe-induced vasoconstriction was mediated by an increased synthesis or preservation of cGMP. Despite an increased release of PGI(2) in the WB group, neither inhibition of PGI(2) or TXA(2) synthase resulted in a different response to Phe between the control and the WB rings. Hence, in the SHR, WB decrease Phe-mediated vasoconstriction under basal conditions by enhancing NO-cGMP signaling without a significant involvement of the COX pathway.
研究人员考察了 8 周对照（C）或 8%w/w 蓝莓（WB）饮食后，野生蓝莓对自发性高血压大鼠（SHR）一氧化氮（NO）和环氧化酶（COX）途径关键信号步骤的作用。在不存在或存在以下抑制剂的情况下，用苯肾上腺素（Phe）刺激 SHR 的主动脉环：可溶性鸟苷酸环化酶（sGC）、磷酸二酯酶-5（PDE(5)）、前列腺素 I(2)（PGI(2)）合酶和血栓素 A(2)（TXA(2)）合酶。此外，通过 NO、环鸟苷单磷酸（cGMP）、PGI(2)和 TXA(2)的浓度来确定这些途径中的酶活性。在 WB 喂养的 SHR 中，Phe 诱导的血管收缩的减弱是由 cGMP 的合成或保存增加介导的。尽管 WB 组中 PGI(2)的释放增加，但在对照组和 WB 环之间，PGI(2)或 TXA(2)合酶的抑制均未导致对 Phe 的反应不同。因此，在 SHR 中，WB 通过增强 NO-cGMP 信号而减少基础条件下 Phe 介导的血管收缩，而 COX 途径的参与不明显。
