断乳后不同饲料构成对大鼠体重、体脂含量及激素敏感性脂肪酶基因表达的影响

Effect of different post-weaning dietary compositions on body fat content and hormone-sensitive lipase gene expression in rats fed with high-fat diet

目的研究断乳后不同饲料构成对高脂膳食大鼠体脂含量及脂肪组织中激素敏感性脂肪酶(HSL)基因表达的影响。方法新生Wistar雄性大鼠24天断乳,按体重随机分为A、B、C、D四组,分别给予高碳水化合物构成的基础饲料、高蛋白质构成饲料、高不饱和脂肪酸和高饱和脂肪酸构成饲料喂养3周。然后均转为基础饲料喂养2周后,按体重将A组随机分为A1、A2两组。A1组继续喂饲基础饲料作为对照组,A2和B、C、D四组给予高脂饲料喂养6周,结束实验;A2组则为高碳水化合物组。动态观察大鼠的体重、体脂含量、血糖变化及白色脂肪组织HSLmRNA水平。结果实验末期,断乳后喂饲高不饱和脂肪酸构成饲料的C组,体重、体脂含量和血糖均显著低于高碳水化合物组A2(P<0·05);断乳后喂饲高蛋白质的B组体重和体脂含量明显低于A2组(P<0·05),但血糖水平高于A2(P>0·05);断乳后摄取高饱和脂肪酸饲料的D组,尽管体重明显低于A2(P<0·05),但血糖和体脂含量与A2组无差异(P>0·05)。动态观察表明,断乳后喂饲高不饱和脂肪酸的C组大鼠,白色脂肪组织HSL基因表达水平持续升高。结论断乳后喂饲高不饱和脂肪酸饲料不仅可以降低高脂膳食大鼠的体重、体脂含量,还可明显改善血糖异常,抑制肥胖形成;对基因表达的调控可能参与早期饮食对后续肥胖的程序性影响。

Objective To study the effects of different postweaning dietary compositions on body fat content and hormone-sensitive lipase（HSL） gene expression in rats fed a high-fat diet. Methods Male Wistar rats weaned on 24 days were randomly divided into A, B, C, D groups and were fed on high carbohydrate, high protein, high unsaturated fatty acid and high saturated fatty acid diet respectively. After 3 weeks, all rats were assigned to basic diet for two weeks, then rats from A group were randomly divided into AI and A2 subgroups. AI subgroup was fed on basic diet continuously. A2 subgroup and B, C and D groups were assigned to high-fat diet for six weeks. Eight rats from each group were sacrificed at the end of different treatments to detect body weight, body fat content and blood glucose level. RT-PCR was used to determine the gene expression of hormone-sensitive lipase in white adipose tissue. Results Body weight, body fat content and blood glucose level in C group were significantly lower than those in A2 subgroup on llweeks（ P 〈 0.05）. The body weight, body fat content in B2 group were significantly lower than those in A2 subgroup（ P 〈 0.05）, but blood glucose level was higher than A2 subgroup on llweeks（ P 〉 0.05）. The body weight in D group was significantly lower than that in A2 subgroup（ P 〈 0.05 ）, but body fat content and blood glucose level were not significantly lower than A2 subgroup on 1 lweeks（ P 〉 0.05） .The expression of HSL in B2 and C group was higher on 9 weeks and 1 lweeks respectively. The HSL mRNA levels in all groups on 3weeks were similar to that on 11 weeks. Conclusion Feeding on high unsaturated-fatty acid diet after weaning may significantly reduce the body weight, body fat content, improve the abnormal blood glucose level in rats induced by high-fat diet. It was suggested that the high unsaturated-fatty acid diet can be reasonable for weaned rats and gene expression regulation may be involved in programming later obesity by early nutrition.