Beier S, Classen H G, Loeffler K, Schumacher E, Thöni H
Department of Pharmacology and Toxicology of Nutrition, University of Hohenheim, Stuttgart, Germany.
Arzneimittelforschung. 1995 Mar;45(3):258-61.
The lower blood pressure of vegetarians might partly be due to the high dietary load with nitrate which--to a certain extent--is further reduced to nitrite and finally to nitric oxide. To test this hypothesis, spontaneously hypertensive rats received drinking water containing 0, 25, 50 or 100 mmol/l NO2 during 56 days. Food was offered ad libitum or was restricted by 20% (pair-feeding) to simulate the lower energy consumption of vegetarians. Blood pressure, which was monitored at regular intervals, was lowered in a dose-dependent manner by nitrite. This effect was reversible and could not be enhanced by energy restriction. In volunteers plasma nitrate levels increased by a factor of 8 to 32 following the ingestion of a nitrate-rich meal, and mean methemoglobin concentrations increased from 1.2% to 2.4% indicating the endogenous formation of nitrite under these conditions.
素食者血压较低可能部分归因于饮食中硝酸盐含量高，硝酸盐在一定程度上会进一步还原为亚硝酸盐，最终转化为一氧化氮。为验证这一假设，自发性高血压大鼠在56天内饮用含0、25、50或100 mmol/l亚硝酸盐的饮用水。随意提供食物或限制20%（配对喂养）以模拟素食者较低的能量消耗。定期监测的血压显示，亚硝酸盐可使血压呈剂量依赖性降低。这种效应是可逆的，能量限制并不能增强这种效应。在志愿者中，摄入富含硝酸盐的食物后，血浆硝酸盐水平增加了8至32倍，平均高铁血红蛋白浓度从1.2%增加到2.4%，表明在这些条件下内源性亚硝酸盐的形成。
