Naito Y, Yoshida H, Nagata T, Tanaka A, Ono H, Ohara N
Department of Pharmacology, Hatano Research Institute, Food and Drug Safety Center, Ochiai 729-5, Hadano, Kanagawa, Japan.
Toxicology. 2000 May 5;146(2-3):197-208. doi: 10.1016/s0300-483x(00)00175-x.
Spontaneously hypertensive rats (SHR) and Wistar Kyoto (WKY) rats were fed a diet containing 10% rapeseed (canola) oil or soybean oil as dietary fat, and given drinking water containing 1% NaCl for 26 weeks. From the 10th week and later, systolic blood pressure in the canola oil group became higher than that in the soybean oil group in each strain. The 26-week feeding of canola oil increased plasma lipids and the neutrophil counts, and decreased the platelet counts. In the canola oil group the heart and kidney tended to become heavier with sporadically found histologic lesions. Acetylcholine- and nitroprusside-induced dilating responses of isolated aortic rings and norepinephrine- and veratridine-induced increases in vascular tone of isolated perfused mesenteric arteries were not different between the two groups in each strain. These results demonstrate that canola oil intake as the only dietary fat elevates blood pressure of the rat provided with drinking water containing 1% NaCl through mechanisms other than blunt dilating response of the blood vessel due to dysfunction of the endothelium or vascular smooth muscle, the augmented response to norepinephrine in the arteries and the increased amount of norepinephrine in the sympathetic nerve endings. The lesions in the heart and kidney in SHR may be related to a strain-specific peripheral vascular deterioration which was disclosed by the extremely high blood pressure in the canola oil group.
自发性高血压大鼠（SHR）和Wistar Kyoto（WKY）大鼠被喂食含有10%菜籽油（低芥酸菜子油）或大豆油作为膳食脂肪的饲料，并饮用含有1%氯化钠的饮用水，持续26周。从第10周及之后，每个品系中，菜籽油组的收缩压均高于大豆油组。连续26周喂食菜籽油会增加血浆脂质和中性粒细胞计数，并降低血小板计数。在菜籽油组中，心脏和肾脏有增重趋势，且偶尔会发现组织学病变。每个品系的两组之间，乙酰胆碱和硝普钠诱导的离体主动脉环舒张反应，以及去甲肾上腺素和藜芦碱诱导的离体灌注肠系膜动脉血管张力增加并无差异。这些结果表明，作为唯一膳食脂肪摄入菜籽油，会使饮用含有1%氯化钠饮用水的大鼠血压升高，其机制并非是由于内皮或血管平滑肌功能障碍导致血管舒张反应减弱、动脉对去甲肾上腺素反应增强以及交感神经末梢去甲肾上腺素含量增加。SHR心脏和肾脏中的病变可能与品系特异性外周血管恶化有关，这在菜籽油组极高的血压中得以体现。
