初断乳大鼠摄入高钙饲料对成年期高脂饲料后解偶联蛋白2基因表达的影响

Influence of ablactation rats' high calcium intake to the expression of uncoupling protein 2 mRNA after adulthood obesity induction

目的通过对初断乳大鼠的高钙干预及成年后的高脂干预,测定大鼠骨骼肌中解偶联蛋白2(UCP2)mRNA的表达水平,探讨生命早期高钙摄入对成年期肥胖形成的影响。方法初断乳雄性Wistar大鼠120只随机分为正常饲料组和高钙饲料低(2%)、中(2.5%)、高剂量(3%)组。高钙干预4周后检测血脂。随后所有大鼠进行为期3周的基础饲料喂养。于第7周末取血检测血脂。将正常饲料组成年大鼠随机分为正常对照组和肥胖诱导组,肥胖诱导组及3个高钙组均喂以高脂饲料,肥胖诱导8周后处死所有大鼠取血检测血脂并冻存骨骼肌RT-PCR法半定量检测UCP 2基因表达水平。结果高脂干预后3个高钙组的体重增长量均低于肥胖诱导组,低剂量和高剂量组的体重增长量与正常对照组没有差别;高剂量组的血清甘油三酯含量明显低于肥胖诱导组,与正常对照组一致;肥胖诱导组和高剂量组的UCP 2基因表达水平明显低于正常对照组、低剂量和中剂量组;中剂量高钙组的表达水平明显高于正常对照组。结论初断乳大鼠的高钙喂养能够持续发挥作用,使其在成年后的高脂饲料喂养期间,UCP2基因表达增强,血脂紊乱得以改善。

Objective To study the influence of early high calcium intake to adulthood obesity through detection the expression of uncoupling protein 2 （UCP2） mRNA in muscle by a reverse transcription polymerase chain reaction （RT-PCR） technique. Methods 120 male Wistar rats were divided randomly into normal control group, high dose calcium group, medium dose calcium group and low doses calcium group, with basic diet and high calcium diet for 4 weeks. After intervention, blood fat was compared. Subsequently, all rats were fed basic diet for 3 weeks and blood fat was compared. Then,normal feed rats were randomly divided into normal controls and obesity induction group. Obesity induction group, high dose calcium group, medium dose calcium group and low doses calcium group were fed high-fat food. After 8 weeks, RT-PCR was used for analysis the expression of UCP2 mRNA in muscle. Results After obesity induction, weight growth of three high calcium groups were below obesity induction group, weight growth of low doses and high doses of high calcium groups were no difference with normal control group. Serum triglyceride levels of high dose high calcium group were significantly lower than obesity induction group and no difference with normal control group. Expression level of UCP2 mRNA of obesity induction group and high doses of high calcium group were obviously lower than normal controls, low dose and medium dose high calcium group, medium dose high calcium group＇ expression was significantly higher than normal control group. Conclusion In rats＇ early life high calcium intake can continue to affect adulthood obesity induced by high-fat feed, increase expression level of UCP2 mRNA, improve the disorder of blood fat metabolism.