Shepherd Anthony I, Wilkerson Daryl P, Fulford Jon, Winyard Paul G, Benjamin Nigel, Shore Angela C, Gilchrist Mark
College of Life and Environmental Sciences, Sport and Health Sciences, University of Exeter, Devon, United Kingdom; University of Exeter Medical School and NIHR Exeter Clinical Research Facility, Royal Devon and Exeter Hospital, Exeter, Devon, United Kingdom; Department of Sport and Exercise Science, Portsmouth, United Kingdom
College of Life and Environmental Sciences, Sport and Health Sciences, University of Exeter, Devon, United Kingdom;
Am J Physiol Gastrointest Liver Physiol. 2016 Sep 1;311(3):G356-64. doi: 10.1152/ajpgi.00203.2016. Epub 2016 Jul 14.
Nitric oxide alters gastric blood flow, improves vascular function, and mediates glucose uptake within the intestines and skeletal muscle. Dietary nitrate, acting as a source of nitric oxide, appears to be a potential low-cost therapy that may help maintain glucose homeostasis. In a randomized, double-blind, placebo-controlled crossover study, 31 young and older adult participants had a standardized breakfast, supplemented with either nitrate-rich beetroot juice (11.91 mmol nitrate) or nitrate-depleted beetroot juice as placebo (0.01 mmol nitrate). MRI was used to assess apparent diffusion coefficient (ADC), portal vein flux, and velocity. Plasma glucose, incretin, and C-peptide concentrations and blood pressure were assessed. Outcome variables were measured at baseline and hourly for 3 h. Compared with a placebo, beetroot juice resulted in a significant elevation in plasma nitrate and plasma nitrite concentration. No differences were seen for the young or older adult cohorts between placebo and beetroot juice for ADC, or portal vein flux. There was an interaction effect in the young adults between visits for portal vein velocity. Nitrate supplementation did not reduce plasma glucose, active GLP-1, total GLP-1, or plasma C-peptide concentrations for the young or older adult cohorts. Despite a significant elevation in plasma nitrite concentration following an acute dose of (11.91 mmol) nitrate, there was no effect on hepatic blood flow, plasma glucose, C-peptide, or incretin concentration in healthy adults.
一氧化氮可改变胃血流量，改善血管功能，并介导肠道和骨骼肌对葡萄糖的摄取。膳食硝酸盐作为一氧化氮的来源，似乎是一种潜在的低成本疗法，可能有助于维持葡萄糖稳态。在一项随机、双盲、安慰剂对照的交叉研究中，31名年轻和年长的成年参与者食用了标准化早餐，并补充了富含硝酸盐的甜菜根汁（11.91 mmol硝酸盐）或作为安慰剂的低硝酸盐甜菜根汁（0.01 mmol硝酸盐）。使用磁共振成像（MRI）来评估表观扩散系数（ADC）、门静脉血流量和速度。评估了血浆葡萄糖、肠促胰岛素和C肽浓度以及血压。在基线和3小时内每小时测量一次结果变量。与安慰剂相比，甜菜根汁导致血浆硝酸盐和血浆亚硝酸盐浓度显著升高。在安慰剂组和甜菜根汁组之间，年轻或年长成人队列的ADC或门静脉血流量没有差异。年轻成年人在各次就诊之间门静脉速度存在交互作用。补充硝酸盐对年轻或年长成人队列的血浆葡萄糖、活性胰高血糖素样肽-1（GLP-1）、总GLP-1或血浆C肽浓度没有降低作用。尽管急性剂量（11.91 mmol）硝酸盐后血浆亚硝酸盐浓度显著升高，但对健康成年人的肝血流量、血浆葡萄糖、C肽或肠促胰岛素浓度没有影响。
