Baba N, Bracco E F, Hashim S A
Lipids. 1987 Jun;22(6):442-4. doi: 10.1007/BF02537276.
The role of brown adipose tissue in the mechanism of medium chain triglyceride (MCT)-induced thermogenesis was investigated. Under anesthesia, the interscapular brown adipose tissue (IBAT) was excised in male Sprague-Dawley rats, and the animals were fitted with gastrostomy tubes. After a 10-day recovery period, the animals were divided into two groups: one group received a diet containing MCT as 50% of calories, and the other group received an isocaloric diet containing long chain triglyceride (LCT). The diets were fed for 6 wk at a level of calorie intake that was 150% of the ad libitum intake of a parallel control group. During the last week of the study, resting and norepinephrine (NE)-stimulated O2 consumption and CO2 production were measured in a Noyons diaferometer. At the end of 6 wk, the animals were weighed and killed. The individual fat pads were dissected and weighed, and an aliquot of the right retroperitoneal fat pad was used to measure adipocyte size and number. The results showed that body weight and adipocyte size (but not adipocyte number) were significantly smaller in the MCT-fed compared to the LCT-fed animals. Resting as well as maximal NE-stimulated oxygen consumption values were significantly higher in the MCT-fed than the LCT-fed rats. It is concluded that the enhanced thermogenesis induced by MCT persists despite the absence of IBAT and that the phenomenon is likely related to more extensive oxidation of MCT- in contrast to LCT-derived fatty acids, thus leading to increased oxygen consumption, enhanced dissipation of energy as heat and diminished efficiency of weight gain and deposition of body fat.
研究了棕色脂肪组织在中链甘油三酯（MCT）诱导的产热机制中的作用。在麻醉状态下，切除雄性Sprague-Dawley大鼠的肩胛间棕色脂肪组织（IBAT），并给动物安装胃造瘘管。经过10天的恢复期后，将动物分为两组：一组给予含MCT且热量占50%的饮食，另一组给予含等热量长链甘油三酯（LCT）的饮食。以平行对照组随意摄入量的150%的热量摄入水平喂食这些饮食6周。在研究的最后一周，使用Noyons测热计测量静息和去甲肾上腺素（NE）刺激后的氧气消耗量和二氧化碳产生量。在6周结束时，对动物进行称重并处死。解剖并称重各个脂肪垫，取右侧腹膜后脂肪垫的一份样品测量脂肪细胞大小和数量。结果表明，与喂食LCT的动物相比，喂食MCT的动物体重和脂肪细胞大小（但不是脂肪细胞数量）明显更小。喂食MCT的大鼠静息以及最大NE刺激后的氧气消耗值明显高于喂食LCT的大鼠。得出的结论是，尽管没有IBAT，MCT诱导的产热增强仍然持续，并且该现象可能与MCT的更广泛氧化有关——与LCT衍生的脂肪酸相比，从而导致氧气消耗增加、能量以热的形式消散增强以及体重增加和体脂沉积的效率降低。
