Sakaguchi T, Arase K, Fisler J S, Bray G A
Department of Medicine, University of Southern California, Los Angeles County/USC Medical Center.
Physiol Behav. 1989 Jun;45(6):1177-82. doi: 10.1016/0031-9384(89)90106-6.
Three experiments have examined the effects of ad lib and forced intake of a high-fat diet on sympathetic firing rate to brown adipose tissue. Seven days after beginning of ad lib intake of either a low-fat or high-fat diet, sympathetic activity was not significantly different in either group nor was it significantly different from the values obtained in animals measured at the switch from the chow to a semisynthetic high- or low-fat diet. After 22 days on the semisynthetic diet, however, the sympathetic firing rate of animals eating the high-fat diet had decreased nearly 25% and was significantly lower than the animals maintained on the semisynthetic low-fat diet or animals studied at the transition from the chow to the low-fat diet. In a second experiment animals were tube-fed for 3, 6 or 9 weeks on a high- or low-fat diet. Sympathetic firing rate of the rats eating the low-fat diet was higher at all three times, but the difference decreased with longer feeding. To eliminate differences in food intake, animals were tube-fed a moderate- or high-fat liquid diet three times a day for six days. The 80 kcal/day intake produced a steady weight gain in both groups. Liver weight, retroperitoneal white adipose tissue weight, and interscapular brown adipose tissue weight were all significantly greater in the animals fed the high-fat diet. Sympathetic firing rate, however, was significantly lower in the animals fed the high-fat semisynthetic diet as compared to animals fed the moderate-fat diet. These data show the high-fat diets are associated with a reduction in sympathetic activity to brown adipose tissue.
三项实验研究了随意进食和强制摄入高脂饮食对棕色脂肪组织交感神经放电频率的影响。在开始随意摄入低脂或高脂饮食7天后，两组动物的交感神经活动均无显著差异，且与从普通饲料转换为半合成高脂或低脂饮食时测量的动物值也无显著差异。然而，在半合成饮食22天后，食用高脂饮食的动物交感神经放电频率下降了近25%，显著低于维持半合成低脂饮食的动物或从普通饲料转换为低脂饮食时研究的动物。在第二项实验中，动物被用高脂或低脂饮食管饲3、6或9周。食用低脂饮食的大鼠在所有三个时间段的交感神经放电频率都较高，但随着喂养时间延长，差异减小。为消除食物摄入量的差异，动物每天三次用中等脂肪或高脂肪液体饮食管饲6天。两组动物每天摄入80千卡热量后体重均稳步增加。喂食高脂饮食的动物肝脏重量、腹膜后白色脂肪组织重量和肩胛间棕色脂肪组织重量均显著更大。然而，与喂食中等脂肪饮食的动物相比，喂食高脂半合成饮食的动物交感神经放电频率显著更低。这些数据表明，高脂饮食与棕色脂肪组织交感神经活动减少有关。
