| 摘要: | 停經後的婦女其體重與體脂盛行率有上升的情形且會增加脂質代謝異常的情況。動物實驗可利用卵巢切除模式，模擬婦女停經後缺乏雌激素的狀況。本研究介入富含n-3脂肪酸的魚油及紫蘇籽油，探討n-3脂肪酸對停經後缺乏雌激素時其脂質代謝及肝臟與心臟功能之影響。32隻8週齡Sprague Dawley雌鼠隨機分成四組：假手術組(C)、卵巢切除組(OC)、卵巢切除魚油組(OF)及卵巢切除紫蘇油組(OP)，實驗期共為16週。每週測量體重及食物攝取量，在16週時犧牲並檢測血液生化值，包括三酸甘油酯(triglyceride, TG)、總膽固醇(total cholesterol, TC)、高密度脂蛋白膽固醇(high density lipoprotein-cholesterol, HDL-C)、adiponectin、leptin濃度，並取肝臟、腎旁及子宮旁白色脂肪組織秤重，測量肝臟調控脂質代謝相關基因的mRNA表現量，如hormone sensitive lipase (HSL)、lipoprotein lipase (LPL)、fatty acid synthase (FAS)、acetyl CoA carboxylase (ACC)、Carnitine palmitoyltransferase I (CPT1)、peroxisome proliferator-activated receptors (PPARs) α以及白色脂肪PPARγ mRNA表現量。各組間食物攝取量皆無顯著差異，體重在卵巢切除的三組皆顯著高於C組。血漿TC濃度OF組顯著低於其他三組，血漿adiponectin濃度OF組顯著高於C組和OP組並與OC組無顯著差異。肝臟外觀OF組有明顯的脂肪肝。肝臟PPARα mRNA表現量OC組顯著高於C組，OF組及OP組顯著低於OC組。子宮旁脂肪組織重OC組顯著高於其他三組。白色脂肪組織PPARγ mRNA表現量實施卵巢切除三組顯著高於C組。以卵巢切除大鼠為模式，介入富含n-3脂肪酸的魚油和紫蘇油，結果顯示n-3脂肪酸可透過增加肝臟PPARα mRNA表現量降低大鼠血漿TG，且降低血糖、 增加HOMA-beta值；紫蘇籽油能降低肝臟三酸甘油脂含量，進而降低脂肪肝指數及發炎指數；魚油透過增加脂肪組織PPARγ mRNA表現量使脂肪細胞平均直徑變小、子宮周圍白色脂肪組織減少，改善體脂肪的堆積；魚油及紫蘇籽油可減少左心室後壁寬及心室中膈厚度，增加心室肌的扭力差及心室肌計算重量，故能改善雌激素缺乏時心臟的功能。
The incidence of overweight and obese population in menopause women is increasing. Ovariectomized (OVX) animal model is widely used in postmenopausal estrogen deficiency studies. Estrogen deficiency is a risk factor for many chronic inflammatory diseases, such as diabetes, dyslipidemia, osteoporosis and obese. Fish oil is an animal source of n-3 polyunsaturated fatty acids; studies showed that increasing n-3 fatty acid intake could regulate lipid metabolism and inflammatory responses. Perilla oil is a plant source oil which also rich in n-3 polyunsaturated fatty acids, especially a-linolenic acid (ALA). ALA can be a precursor of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) these very long chain fatty acids, it is plausible that dietary ALA exerts similar physiological effect as in the case of very long chain fatty acids in fish oil. Thus, the aim of this study was to investigate the effect of different sources n-3 fatty acids on lipid metabolism, liver and heart function in OVX rats model. Twenty-four female 8-week-old Sprague-Dawley rats were divided into four groups: sham-operated group (C), OVX control (OC), OVX- fish oil (OF) group and OVX- perilla oil (OP) group. Fish oil groups and perilla oil groups adjusted diet n-3/n-6 fatty acids ratio to 1/2. After four months treatment, the all animals were scarified and blood, liver, heart, and abdominal adipose tissue were collected for analysis. Results showed that compared with the sham-operation group, body weight and parametrial fat pad weight of the OVX group were significantly increased. Compared to C or OC group, OVX rats fed with fish oil or perilla oil decreased plasma TG and TC. Additionally, liver SREBP-1c and FAS mRNA expressions were significantly lower in OF group as compared with OC group and C group, respectively. Liver PPARα mRNA expression significantly decreased in OF and OP group compared with OC group. Fish oil and perilla oil treatment could decrease adiposity diameter and increase adipose tissue PPARγ mRNA expression. Furthermore, the OF and OP groups decreased left ventricular posterior wall thickness and interventricular septum depth, improving the heart functions. The present findings suggest that treatment with perilla oil may alleviate liver steatosis by modulating gene expression related to lipid metabolism. Fish oil decreased adiposity diameter via upregulation of PPARγ mRNA expression to improve abdominal fat accumulation. |
