Nkanu Etah E, Owu Daniel U, Osim Eme E
a Department of Physiology , Cross River University of Technology , Okuku Campus, Yala , Nigeria.
b Department of Physiology , University of Calabar , Calabar , Nigeria.
J Diet Suppl. 2018 Jul 4;15(4):431-444. doi: 10.1080/19390211.2017.1350248. Epub 2017 Dec 27.
Intake of thermally oxidized palm oil leads to cytotoxicity and alteration of the potassium ion channel function. This study investigated the effects of fresh and thermally oxidized palm oil diets on blood pressure and potassium ion channel function in blood pressure regulation. Male Wistar rats were randomly divided into three groups of eight rats. Control group received normal feed; fresh palm oil (FPO) and thermally oxidized palm oil (TPO) groups were fed a diet mixed with 15% (weight/weight) fresh palm oil and five times heated palm oil, respectively, for 16 weeks. Blood pressure was measured; blood samples, hearts, and aortas were collected for biochemical and histological analyses. Thermally oxidized palm oil significantly elevated basal mean arterial pressure (MAP). Glibenclamide (10 mmol/L) and tetraethylammonium (TEA; 10 mmol/L) significantly raised blood pressure in TPO compared with FPO and control groups. Levcromakalim (10 mmol/L) significantly (p < .01) reduced MAP by 32.0% in FPO and by 5.4% in TPO. NS1619 (10 mmol/L) significantly (p < .01) decreased MAP by 19.5% in FPO and by 8% in TPO. The TPO significantly (p < 0.01) increased the tissue levels of peroxide, total cholesterol, triglyceride, and low-density lipoprotein cholesterol while catalase and superoxide dismutase activities were significantly (p < .01) decreased compared with control and FPO groups. Histological alterations were prominent in aortas and hearts of rats in the TPO group. These results suggest that prolonged consumption of repeatedly heated palm oil increases MAP probably due to the attenuation of adenosine triphosphate-sensitive potassium (K) and large-conductance calcium-dependent potassium (BK) channels, tissue peroxidation, and altered histological structures of the heart and blood vessels.
摄入热氧化棕榈油会导致细胞毒性以及钾离子通道功能改变。本研究调查了新鲜棕榈油和热氧化棕榈油饮食对血压及血压调节中钾离子通道功能的影响。雄性Wistar大鼠被随机分为三组，每组八只。对照组给予正常饲料；新鲜棕榈油（FPO）组和热氧化棕榈油（TPO）组分别喂食含15%（重量/重量）新鲜棕榈油和经过五次加热的棕榈油的饲料，持续16周。测量血压；采集血液样本、心脏和主动脉用于生化和组织学分析。热氧化棕榈油显著升高基础平均动脉压（MAP）。与FPO组和对照组相比，格列本脲（10 mmol/L）和四乙铵（TEA；10 mmol/L）显著升高TPO组的血压。左卡尼汀（10 mmol/L）显著（p <.01）降低FPO组MAP的32.0%，降低TPO组MAP的5.4%。NS1619（10 mmol/L）显著（p <.01）降低FPO组MAP的19.5%，降低TPO组MAP的8%。与对照组和FPO组相比，TPO组显著（p < 0.01）增加了组织中过氧化物、总胆固醇、甘油三酯和低密度脂蛋白胆固醇的水平，而过氧化氢酶和超氧化物歧化酶的活性显著（p <.01）降低。TPO组大鼠的主动脉和心脏出现明显的组织学改变。这些结果表明，长期食用反复加热的棕榈油可能会升高MAP，这可能是由于三磷酸腺苷敏感性钾（K）通道和大电导钙依赖性钾（BK）通道功能减弱、组织过氧化以及心脏和血管组织结构改变所致。
