断乳后饲料构成对大鼠肝脏CPT-ⅠmRNA表达影响

Effects of postweaning dietary compositions on hepatic CPT-Ⅰ mRNA expression in rats

目的研究断乳后饲料构成对大鼠肝脏肉碱棕榈酰转移酶-I(CPT-I)mRNA表达的影响。方法新生Wistar雄性大鼠24 d断乳,按体重随机分为A、B、C、D 4组,分别喂饲高碳水化合物、高蛋白质、高不饱和脂肪酸和高饱和脂肪酸构成饲料3周后,基础饲料喂养2周,A组按体重随机再分为A1、A2 2组。A1组喂饲基础饲料作为对照组,A2和B、C、D 4组给予高脂饲料喂养6周,A2组作为高碳水化合物组。动态检测大鼠的体重、体脂含量、血糖及肝脏肉碱棕榈酰转移酶-I mRNA水平。结果实验末期,C组大鼠体重、体脂含量和血糖均明显低于A2组(P<0.05);B组大鼠体重和体脂含量明显低于A2组(P<0.05),但血糖水平高于A2组;D组大鼠体重明显低于A2组(P<0.05),但血糖和体脂含量与A2组差异无统计学意义(P>0.05)。动态观察表明,C组大鼠CPT-I mRNA水平持续升高,且在实验末期明显高于其他组。结论断乳后进食高不饱和脂肪酸构成饲料可能通过持续增加CPT-I基因表达,抑制大鼠肥胖形成。

Objective To study the effects of postweaning dietary compositions on hepatic CPT-Ⅰ gene expression in rats. Methods Male Wistar rats weaned on 24 d were randomly divided into A, B, C, D groups and were fed a high carbohydrate, high protein, high unsaturated fatty acid and high saturated fatty acid diet respectively. After three weeks, all rats were assigned to basic diet for 2 weeks, then rats from A group were randomly divided into groups A 1 and A2. A 1 was fed on basic diet continuously. Groups A2 , B, C, and D were assigned to high - fat diet for six weeks. Eightrats from each group were sacrificed at the end of experiment to detect body weight, body fat content and blood glucose level. RT - PCR were used to determine the expression of CPT-Ⅰ in liver tissue. Results Body weight, body fat and blood glucose level in C group were significantly lower than those in A2 on llw （ P 〈 0.05 ）. The body weight, body fat content in B group were significandy lower than that in A2 （P〈0.05）.However, blood glucose level was higher than A2 on 1 lw （P〉0.05）.The body weight in D group was significantly lower than that in A2 （ P〈 0.05）, but body fat content and blood glucose levels were not significantly lower than A2 on 1 lw （P 〉 0.05）. The CPT-Ⅰ mRNA level in C group was persistendy increased to be the highest among all groupsduring experiment and higher than that of other groups at the end of the experiment significantly. Conclusion Feeding on high unsaturated - fatty acid diet after weaning may significantly inhibit the obesity oeeurance, improve the abnormal blood glucose level in rats fed with high - fat diet. Persistently increased CPT - Ⅰ gene expression may be involved in inhibiting later obesity by early nutrition.