不同n-6/n-3PUFA比率对载脂蛋白E缺失小鼠脂质成分的影响

Effect of Various Ratios of n-6/n-3 Polyunsaturated Fatty Acids on Lipid Composition in Apolipoprotein E Deficient Mice

目的探讨不同n-6/n-3多不饱和脂肪酸(polyunsaturated fatty acid,PUFA)饮食对载脂蛋白E缺失(apolipoprotein E deficient,apo E-/-)小鼠血脂水平及脂质成分的影响,以冀为高脂血症患者的日常膳食提供参考。方法 8周龄雄性apo E-/-小鼠随机分为5组(n=12),在基础鼠粮基础上添加紫苏籽油和红花油,使n-6/n-3 PUFA比率为:组1 1.28,组2 5.03,组3 9.98,组4 68.26,总脂肪量5%,对照组饮食基础鼠粮,干预6周后检测血清脂质水平,气相色谱-质谱联用仪分析血清和肝脏组织中脂肪酸组成。结果与其余各组相比,组4血清甘油三酯(TG)水平升高;与对照组相比,4种饮食干预均显著降低血清低密度脂蛋白胆固醇酯(LDL-C)水平,其中组3饮食降低程度最大;组4与组1相比,血清和肝脏组织中n-6脂肪酸分别增加了28%和48%,花生四烯酸(arachidonic acid,AA)分别增加了118%和122%,亚油酸(linoleic acid,LA)分别增加了19%和29%;总n-3 PUFA分别降低了39%和44%,二十碳五烯酸(EPA)分别降低了63%和65%。结论随着饮食中n-6/n-3 PUFA比率的增加,血清和肝脏组织中n-6 PUFA含量增加,n-3 PUFA含量降低。n-6/n-3 PUFA比率9.98饮食可最大程度降低血清LDL-C水平,可作为高脂血症患者的日常膳食参考。

Objective To explore the effects of different dietary n-6/n-3 polyunsaturated fatty acids（PUFA） on serum lipids and the fatty acids composition of serum and liver tissue in apolipoprotein E deficient（apo E-/-） mice with similar features to those observed in humans with type III familial hyperlipoproteinemia.Methods The male mice at the age of 8 weeks were randomly assigned to four experimental groups（fed experimental diets） and one control group（fed control diet）（n=12,respectively）,and the diet intervention lasted for 6 weeks.The experimental diets were made by adding perilla seed oil and safflower oil based on the control diet.The n-6/n-3 PUFA ratios of the experimental diets,for groups 1-4,were 1.28,5.03,9.98 and 68.26,respectively.The total fat accounted for 5 %（w/w） of the diet.At the end of the feeding period,all mice were sacrificed.The serum lipids and the fatty acids composition in serum and liver tissue were analyzed.Results The results showed that the serum LDL-C level of group 3 was significant lower than those of other groups after feeding the experimental diets for 6 weeks.The serum triglyceride（TG） concentration of group 4 was higher than those of other groups.The n-6 PUFA in serum and liver in group 4 increased 28 % and 48 %,arachidonic acid（AA） increased 118 % and 122 %,linoleic acid（LA） increased 19 % and 29 %,respectively,compared with group 1.The n-3 PUFA in serum and liver in group 4 decreased 39 % and 44 %,and eicosapentaenoic acid（EPA） decreased 63 % and 65 %,respectively,compared with group 1.Conclusion As the dietary ratio of n-6/n-3 fatty acids ascended,so did the level of total n-6 PUFA in serum and liver,and the concentration of total n-3 fatty acids declined.The n-6/n-3 PUFA ratio of 9.98 could decrease LDL-C level obviously,which was the dietary proposal for the patients with hyperlipoproteinemia.