Barsalani Razieh, Pighon Abdolnaser, Rabasa-Lhoret Rémi, Yasari Siham, Lavoie Jean-Marc
Department of Kinesiology, University of Montreal, Montreal, Québec, Canada.
Physiol Behav. 2008 Sep 3;95(1-2):216-21. doi: 10.1016/j.physbeh.2008.05.024. Epub 2008 Jun 10.
Ovarian hormones have been shown to regulate liver lipid accumulation in rats. The present study was designed to evaluate liver lipid resorption in ovariectomized (Ovx) rats. Ovx and sham-operated (Sham) rats were submitted to a high-fat (HF; 43% kcal fat as energy) diet for 5 weeks and then either maintained on this diet or switched to a standard (SD; 12.5% kcal fat as energy) diet till weeks 8 and 13 (n=8 rats/group). Body weight, energy intake, liver and intra-abdominal fat accumulation and plasma metabolic profile were determined. Body weight was significantly (P<0.01) higher in Ovx than in Sham groups at all times and switching diet did not alter the body weight pattern. The weight of the intra-abdominal fat depots and plasma leptin levels, along with liver triacylglycerol (TAG) concentrations, were significantly higher (P<0.01) in Ovx than in Sham rats. Switching diet reduced intra-abdominal fat depot weight and plasma leptin in all groups. Switching diet also resulted in a decrease in liver fat accumulation in Sham rats at all times. However, 8 weeks after the diet switch (week 13) liver fat accumulation was as high in Ovx rats as those maintained on the HF diet. When liver TAG values measured at week 13 were compared to initial pre-switching values (week 5), liver TAG levels in Ovx animals were maintained at the same level independently of the diet switch, while in Sham rats switching to a SD diet reduced liver TAG accumulation (P<0.05). The same comparisons with plasma TAG levels revealed an opposite relationship. These data suggest that liver lipid resorption in Ovx animals is more related to the ovarian hormone status than to the type of ingested diet.
卵巢激素已被证明可调节大鼠肝脏脂质蓄积。本研究旨在评估去卵巢（Ovx）大鼠的肝脏脂质吸收情况。将Ovx大鼠和假手术（Sham）大鼠给予高脂（HF；43%千卡脂肪作为能量）饮食5周，然后维持该饮食或改为标准（SD；12.5%千卡脂肪作为能量）饮食直至第8周和第13周（每组n = 8只大鼠）。测定体重、能量摄入、肝脏和腹腔内脂肪蓄积以及血浆代谢谱。在所有时间点，Ovx组的体重均显著高于Sham组（P<0.01），且饮食转换并未改变体重模式。Ovx大鼠的腹腔内脂肪库重量、血浆瘦素水平以及肝脏三酰甘油（TAG）浓度均显著高于Sham大鼠（P<0.01）。饮食转换使所有组的腹腔内脂肪库重量和血浆瘦素降低。饮食转换还导致Sham大鼠在所有时间点的肝脏脂肪蓄积减少。然而，饮食转换8周后（第13周），Ovx大鼠的肝脏脂肪蓄积与维持高脂饮食的大鼠一样高。将第13周测得的肝脏TAG值与转换前初始值（第5周）进行比较时，Ovx动物的肝脏TAG水平无论饮食转换与否均维持在同一水平，而Sham大鼠改为SD饮食则降低了肝脏TAG蓄积（P<0.05）。与血浆TAG水平进行同样比较时发现了相反的关系。这些数据表明，Ovx动物的肝脏脂质吸收与卵巢激素状态的关系比与摄入饮食类型的关系更大。
