Department of Pharmacology, Faculty of Medicine, Universiti Kebangsaan Malaysia, Jalan Raja Muda Abdul Aziz, 50300 Kuala Lumpur, Malaysia.
Lipids Health Dis. 2010 Jun 23;9:66. doi: 10.1186/1476-511X-9-66.
Poor control of blood pressure leads to hypertension which is a major risk factor for development of cardiovascular disease. The present study aimed to explore possible mechanisms of elevation in blood pressure following consumption of heated vegetable oil.
Forty-two male Sprague-Dawley rats were equally divided into six groups: Group I (control)--normal rat chow, Group II--fresh soy oil, Group III--soy oil heated once, Group IV--soy oil heated twice, Group V--soy oil heated five times, Group VI--soy oil heated ten times. Blood pressure was measured at the baseline level and at a monthly interval for six months. Plasma nitric oxide, heme oxygenase and angiotensin-converting enzyme levels were measured prior to treatment, at month-three and month-six later. At the end of treatment, the rats were sacrificed and thoracic aortas were taken for measurement of vascular reactivity.
Blood pressure increased significantly (p<0.01) in the repeatedly heated oil groups compared to the control and fresh soy oil groups. Consumption of diet containing repeatedly heated oil resulted higher plasma angiotensin-converting enzyme level and lower nitric oxide content and heme oxygenase concentration. Reheated soy oil groups exhibited attenuated relaxation in response to acetylcholine or sodium nitroprusside, and greater contraction to phenylephrine.
As a result of consumption of repeatedly heated soy oil, an elevation in blood pressure was observed which may be due to the quantitative changes in endothelium dependent and independent factors including enzymes directly involved in the regulation of blood pressure.
血压控制不佳会导致高血压，这是心血管疾病发展的主要危险因素。本研究旨在探讨食用加热植物油后血压升高的可能机制。
42 只雄性 Sprague-Dawley 大鼠平均分为六组：I 组（对照组）——正常大鼠饲料；II 组——新鲜大豆油；III 组——加热一次的大豆油；IV 组——加热两次的大豆油；V 组——加热五次的大豆油；VI 组——加热十次的大豆油。在基线水平和每月间隔测量血压，共六个月。在治疗前、治疗后三个月和六个月测量血浆一氧化氮、血红素氧合酶和血管紧张素转换酶水平。治疗结束时，处死大鼠，取胸主动脉测量血管反应性。
与对照组和新鲜大豆油组相比，反复加热油组的血压显著升高（p<0.01）。食用含反复加热油的饮食会导致血浆血管紧张素转换酶水平升高，一氧化氮含量和血红素氧合酶浓度降低。再加热大豆油组对乙酰胆碱或硝普钠的舒张反应减弱，对苯肾上腺素的收缩反应增强。
由于食用反复加热的大豆油，血压升高，这可能是由于直接参与血压调节的内皮依赖性和非依赖性因素（包括酶）的定量变化所致。
