Department of Bio-Science and Engineering, Shibaura Institute of Technology, Fukasaku, Munumaku Saitama, Japan.
PLoS One. 2014 Apr 16;9(4):e94853. doi: 10.1371/journal.pone.0094853. eCollection 2014.
Several systematic reviews have reported that flow mediated dilatation (FMD) was significantly increased in subjects after ingestion of chocolate that contains flavan-3-ols; however, the mechanisms responsible for this effect are not clear. In this study, we evaluated the effects of a single oral dose of flavan-3-ols on the systemic circulation and microcirculation in the cremaster muscle using intravital video microscopy in vivo. The cremaster muscle in rats was spread over a plastic chamber and a gastric tube was placed into the stomach. Blood flow in the cremasteric artery was determined using a laser Doppler flowmeter, while blood pressure and heart rate were measured by the tail-cuff method. Red blood cell velocity in arterioles and blood flow in the artery were significantly increased 5 min after the administration of 10 mg/kg flavan-3-ols compared with distilled water treatment. The number of capillaries recruited in the cremaster muscle was also significantly increased 15 min after treatment. Microscopic observation confirmed that increased shear stress on endothelial cells was maintained during the measurement period. The mean arterial blood pressure and heart rate were also significantly elevated soon after administration and returned to baseline before the end of the observation period. Plasma nitrate and nitrite levels, and NO phosphorylation of aortic tissue were significantly increased at 60 min after administration of flavan-3-ols. According to these results, a single oral dose of flavan-3-ols elevates blood pressure and flow transiently, and these effects induce NO production through increased shear stress on endothelial cells.
几项系统评价报告称，摄入含有黄烷-3-醇的巧克力后，受试者的血流介导扩张（FMD）显著增加；然而，这种作用的机制尚不清楚。在这项研究中，我们使用活体体内视频显微镜评估了单次口服黄烷-3-醇对精索肌系统循环和微循环的影响。将大鼠的精索肌铺在塑料室上，并将胃管放入胃中。使用激光多普勒血流仪测定精索动脉的血流，通过尾套法测量血压和心率。与蒸馏水治疗相比，给予 10mg/kg 黄烷-3-醇后 5 分钟，微动脉中红细胞速度和动脉血流显著增加。精索肌募集的毛细血管数量在治疗 15 分钟后也显著增加。显微镜观察证实，在测量期间，内皮细胞上的剪切应力增加得以维持。给药后平均动脉压和心率也显著升高，并在观察期结束前恢复到基线。给予黄烷-3-醇 60 分钟后，血浆硝酸盐和亚硝酸盐水平以及主动脉组织的 NO 磷酸化显著增加。根据这些结果，单次口服黄烷-3-醇可使血压和血流短暂升高，这些作用通过增加内皮细胞的剪切应力诱导 NO 产生。
