Harrold J A, Widdowson P S, Clapham J C, Williams G
Diabetes and Endocrinology Research Group, Department of Medicine, University of Liverpool, Liverpool L69 3GA, United Kingdom.
Am J Physiol Endocrinol Metab. 2000 Aug;279(2):E340-7. doi: 10.1152/ajpendo.2000.279.2.E340.
We investigated the relative importance of overeating, thermogenesis, and uncoupling protein (UCP) expression in determining the severity of obesity in male Wistar rats fed a highly palatable diet. After 2 wk of feeding, body weight did not differ significantly from controls (248 +/- 4 vs. 229 +/- 3 g; P > 0.3), but rectal temperature, brown adipose tissue (BAT) mass, UCP3 expression in gastrocnemius muscle, and UCP2 expression in white adipose tissue (WAT) were all elevated in diet-fed animals. In a further study, rats fed a palatable diet for 8 wk exhibited higher energy intake and rectal temperature than controls. Dietary-obese rats were divided into high (427-490 g; n = 8) and low (313-410 g; n = 10) weight gainers. The high gainers ate significantly more than the low gainers, and energy intake was positively correlated with weight gain (r(2) = 0.72, P < 0.01). UCP2 and UCP3 mRNA levels in gastrocnemius muscle were significantly increased above lean controls in all diet-fed animals, whereas UCPs in WAT and BAT did not differ significantly from controls. Whereas rats fed palatable food exhibited a thermogenic response, there was no significant difference in core temperature between high and low gain groups (37. 5 +/- 0.1 vs. 37.6 +/- 0.1 degrees C; P > 0.5). We conclude that a higher energy intake is the critical factor determining susceptibility to dietary obesity in unselected Wistar rats.
我们研究了暴饮暴食、产热以及解偶联蛋白（UCP）表达在决定喂食美味食物的雄性Wistar大鼠肥胖严重程度方面的相对重要性。喂食2周后，体重与对照组相比无显著差异（248±4克对229±3克；P>0.3），但喂食该饮食的动物直肠温度、棕色脂肪组织（BAT）质量、腓肠肌中UCP3表达以及白色脂肪组织（WAT）中UCP2表达均升高。在进一步研究中，喂食美味食物8周的大鼠比对照组表现出更高的能量摄入和直肠温度。饮食诱导肥胖的大鼠被分为高体重增加组（427 - 490克；n = 8）和低体重增加组（313 - 410克；n = 10）。高体重增加组的食量显著多于低体重增加组，且能量摄入与体重增加呈正相关（r² = 0.72，P < 0.01）。所有喂食该饮食的动物中，腓肠肌中UCP2和UCP3 mRNA水平均显著高于瘦对照组，而WAT和BAT中的UCPs与对照组无显著差异。虽然喂食美味食物的大鼠表现出产热反应，但高体重增加组和低体重增加组的核心温度无显著差异（37.5±0.1对37.6±0.1℃；P>0.5）。我们得出结论，较高的能量摄入是决定未筛选的Wistar大鼠对饮食诱导肥胖易感性的关键因素。
