Department of Nutrition and Food Hygiene, Public Health College, Harbin Medical University, Harbin, 150081, China.
J Nutr Biochem. 2012 Oct;23(10):1238-44. doi: 10.1016/j.jnutbio.2011.07.004. Epub 2011 Dec 29.
The aim of this study was to investigate the effects of a postweaning low-calcium diet on later obesity and explore the underlying mechanisms. Ninety-six male rats were weaned at 3 weeks of age, fed standard (STD: 0.50% calcium, n=48) and low-calcium (LC: 0.15% calcium, n=48) diets for 3 weeks, and then fed the standard diet for a 3-week washout period successively. Finally, the STD rats were divided into STD control and high-fat diet (HFD) groups, and the LC ones into LC control and LC+HFD (LCHF) groups. The STD and LC rats were fed the standard diet, while the HFD control and LCFD ones were fed a high-fat diet for 6 weeks to induce obesity. During the three feeding periods, adenosine-monophosphate-activated protein kinase (AMPK) and its responsive proteins phospho-acetyl-coA carboxylase, carnitine palmitoyltransferase 1 and uncoupling protein 3 were persistently down-regulated in the LC group (decreased by 18%, 24%, 18% and 20%, respectively) versus the STD group, and these effects were significantly more pronounced in the LCHFD group (decreased by 21%, 30%, 23% and 25%, respectively) than the HFD group by a later high-fat stimuli, causing more fat and body weight in adulthood. However, lipolysis enzymes, serum leptin, insulin and lipids were not significantly affected until the body weight and fat content changed at 15 weeks of age. The results suggest that the low-calcium diet after weaning promotes rat adult-onset obesity induced by high-fat diet, which might be achieved by programming expressions of genes involved in AMPK pathway.
本研究旨在探讨断乳后低钙饮食对后期肥胖的影响，并探讨其潜在机制。96 只雄性大鼠于 3 周龄断奶，分别给予标准（STD：0.50%钙，n=48）和低钙（LC：0.15%钙，n=48）饮食 3 周，然后连续 3 周给予标准饮食洗脱期。最后，将 STD 大鼠分为 STD 对照组和高脂肪饮食（HFD）组，LC 大鼠分为 LC 对照组和 LC+HFD（LCHF）组。STD 和 LC 大鼠给予标准饮食，而 HFD 对照组和 LCFD 组给予高脂肪饮食 6 周诱导肥胖。在三个喂养期内，AMPK 及其反应蛋白磷酸乙酰辅酶 A 羧化酶、肉碱棕榈酰基转移酶 1 和解偶联蛋白 3 在 LC 组中持续下调（分别减少 18%、24%、18%和 20%），而在 LCHFD 组中更为明显（分别减少 21%、30%、23%和 25%），这是由后期高脂肪刺激引起的，导致成年后更多的脂肪和体重。然而，脂解酶、血清瘦素、胰岛素和脂质在 15 周龄体重和脂肪含量发生变化之前没有明显变化。结果表明，断乳后低钙饮食促进高脂肪饮食诱导的大鼠成年肥胖，这可能是通过编程 AMPK 途径相关基因的表达来实现的。
