多不饱和脂肪酸不同配比对大鼠血脂影响

Effects of different ratios of n-3 to n-6 polyunsaturated fatty acids on lipid metabolism of SD rats

目的研究不同n-3/n-6配比的多不饱和脂肪酸(PUFA)对大鼠血脂影响。方法将58只SD大鼠根据血清总胆固醇(TC)水平随机分为6组,分别给予基础饲料、高脂饲料和添加n-3/n-6不同配比PUFA的高脂或基础饲料。于第15,30,45 d分别测血脂水平,第45 d取脂肪组织称重并测肝组织中过氧化物酶体增殖物激活受体γ(PPAR-γ)和腺苷酸活化蛋白激酶α2(AMPK-α2)的mRNA表达。结果摄入添加PUFA膳食的4组大鼠45d后血清甘油三酯(TG)分别为(1.15±0.37),(1.25±0.56),(1.00±0.25),(1.17±0.30)mmol/L,均明显低于高脂组的(1.73±0.33)mmol/L;TC分别为(1.80±0.18),(1.89±0.20),(1.41±0.21),(1.58±0.16)mmol/L,均明显低于高脂组的(2.23±0.19)mmol/L;低密度脂蛋白胆固醇(LDL-C)分别为(1.00±0.23),(1.25±0.18),(1.06±0.13),(1.25±0.14)mmol/L,均明显低于高脂组的(1.53±0.27)mmol/L;其脂体比、PPAR-γmRNA、AMPK-α2mRNA表达量均明显高于高脂组,差异均有统计学意义(P<0.05)。结论PUFA改善大鼠高血脂并降低脂肪积累,可能与肝组织AMPK和PPAR-γ等脂肪酸氧化基因表达增加有关。

Objective To study the effects of different ratios of n-3/n-6 polyunsaturated fatty acids（PUFA） in feed on lipid metabolism of SD rats. Methods According to their total serum cholesterol level,58 male Sprague-Dawley rats were randomly divided into 6 groups, and were supplied with common diet, high fat diet, high fat diet with n-3/n-6 PUFA of 1： 1, high fat diet with n-3/n-6 PUFA of 1： 5, common diet with n - 3/n - 6 PUFA of 1： 1, and common diet with n-3/n-6 PU- FA of 1：5 ,respectively. We collected blood samples at 15,30,45 days and measured the lipid level in the plasma. After 45 days, the rats were sacrificed, and adipose tissues （subcutaneous, mesenteric,retroperitoneal, epididymal） were removed and weighed. Also, we measured the expression of peroxisome proliferator-activated receptor γ （PPARγ） and AMPK-α2 in the liver. Results Four diets with different ratios of n-3/n-6 PUFA resulted in significant lower contents of triglycerides（ 1.15 ± 0. 37,1.25 ± 0. 56,1.00± 0. 25,1.17 ± 0. 30 vs 1.73 ± 0. 33 mmol/L）, total cholesterol （ 1.80 ± 0. 18,1. 89 ±0.20,1.41 ± 0. 21,1.58 ± 0. 16 vs 2. 23 ± 0. 19 mmol/L） and LDL cholesterol （ 1.00 ± 0. 23,1.25± 0. 18,1.06 ± 0. 13,1.25 ± 0. 14 vs 1.53 ±0.27 mool/L） in the plasma compared with the high fat diet group（P 〈0.05）. The PPAR-γ and AMPK - α2 mRNA level in the liver increased significantly in the four PUFA diets compared with that of the high fat group（ P 〈 0. 05 ）. Conclusion These results indicate that dietary PUFA can improve Lipid metabolism and decrease fats accumulation, which may be related with the increased expression of fatty acid oxidation gene PPARγ and AMPK.