中文摘要：

目的探讨n-3多不饱和脂肪酸（n-3PUFAs）对血浆脂蛋白脂酶（LPL）无活性单体及活性二聚体表达的影响。方法将3～4周龄清洁级C57BL/6J雄性小鼠随机分为3组,分别予n-3PUFAs缺乏饲料、n-3PUFAs低水平（n-6/n-3PUFAs=15：1）和n-3PUFAs高水平（n-6/n-3PUFAs=1：1）饲料喂养3个月。禁食12h后,每组小鼠随机分为二部分,一部分直接心脏取血,另一部分经股静脉注射肝素（每只10U）后5min取血。血浆LPL活性采用水解三酰甘油生成游离脂肪酸的反应进行测定;血浆中LPL单体及二聚体的表达采用蛋白质免疫印迹法进行分析。结果无论在正常情况下（无肝素注射）还是使用肝素注射,高水平、低水平n-3PUFAs饲料组小鼠血浆LPL活性均显著高于n-3PUFAs缺乏组（Pa〈0.05）。与n-3PUFAs缺乏组比较,无论是无肝素注射还是肝素注射的情况下,n-3PUFAs高水平组血浆LPL二聚体的表达量均显著增加（Pa〈0.05）;n-3PUFAs低水平组LPL二聚体的表达无明显变化。血浆LPL单体的表达在各组间均未见明显改变。结论 n-3PUFAs可促进小鼠血浆LPL二聚体的表达,有助于提升血浆LPL的活性、降低血浆三酰甘油水平。

英文摘要：

Objective To investigate the effect of n-3 polyunsaturated fatty acids（n-3 PUFAs）on expressions of dimeric and monomeric lipoprotein lipase（LPL）.Methods C57BL/6J male mice aged 3-4 weeks were fed for 3 months with 3 different types of diets,included high content of n-3 PUFAs（n-6/n-3 PUFAs was 1：1）,low content of n-3 PUFAs（n-6/n-3 PUFAs was 15：1）and n-3 PUFAs deficiency,respectively.After fasted for 12 hours,within each group,some mice were drawn blood directly,and others were drawn blood at 5 minutes that followed by intravenous injection of heparin（each mouse was injected for 10 U）.Plasma LPL activity was analyzed by incubating plasma with lipid emulsions containing long-chain triglycerides and determining the free fatty acids released.Western blot was used to measure the expression of LPL dimer and monomer.Results With or without heparin injection,plasma LPL activities in the two n-3 PUFA containing diet groups were higher than that in n-3 PUFA deficient group（Pa0.05）.Compared with n-3 PUFA deficient diet group,the expressions of LPL dimers in the group with high content of n-3 PUFAs were markedly increased（Pa0.05）,and no changes was found in low n-3 PUFAs diet group.No difference was shown in the expressions of LPL monomers among all experimental groups.Conclusion n-3 PUFAs can promote LPL dimer expression and increase the activity of plasma LPL in mice,contribute the lower plasma triglyceride concentration.