论文部分内容阅读
目的观察鱼油和亚麻油n-3多不饱和脂肪酸(n-3PUFAs)饲料对小鼠脑聚集二十二碳六烯酸(DHA)水平及各磷脂中DHA水平的影响是否存在差异。方法选择3～4周龄清洁级C57BL/6J雌性小鼠,分别予鱼油n-3PUFAs(富含DHA)饲料、亚麻油n-3PUFAs[富含亚麻酸(LNA)]及n-3PUFAs缺乏(葵花籽油)饲料喂养12周。2种n-3PUFAs饲料中n-3/n-6PUFAs的比值均为1:1,n-6PUFAs来源于葵花籽油。采用薄层层析分离4种脑磷脂[磷脂酰丝氨酸(PS)、磷脂酰乙醇胺(PE)、磷脂酰肌醇(PI)和磷脂酰胆碱(PC)],采用甲酯化-气相色谱分析方法对脑总体脂肪酸及各磷脂成分中的脂肪酸进行测定。结果2组n-3PUFAs饲料均提升了小鼠血浆和脑中的DHA水平。与亚麻油n-3PUFAs饲料组[(4.95±0.15)%]比较,鱼油n-3PUFAs饲料组小鼠血浆DHA水平[(2.04±0.43)%]显著降低;但脑总DHA水平[(15.92±0.26)%vs(16.68±0.20)%]及总n-3PUFAs(∑n-3PUFAs)水平[(21.24±0.33)%vs(22.56±0.14)%]升高,花生四烯酸(AA)水平[(10.28±0.05)%vs(9.02±0.05)%]及总n-6PUFAs(∑n-6PUFAs)水平[(13.33±0.11)%vs(11.05±0.12)%]降低,从而导致AA/DHA比值(0.65±0.01vs0.54±0.01)和∑n-6PUFAs/∑n-3PUFAs比值(0.63±0.01vs0.51±0.01)均降低。对4种脑磷脂脂肪酸分析显示,与亚麻油n-3PUFAs饲料比较,鱼油n-3PUFAs饲料组PS、PE、PI和PC中DHA、AA水平未出现显著性变化,但PE中AA/DHA比值(0.63±0.05vs0.52±0.03)及∑n-6PUFAs/∑n-3PUFAs比值(0.66±0.10vs0.56±0.05)均显著降低(Pa<0.05)。结论单纯饮食摄入LNA对于小鼠脑聚集DHA的效果不如直接摄入现成的DHA好,即脑更倾向于利用现成的DHA,而不是其前体LNA转化来的DHA。
Objective To observe whether fish oil and linseed n-3 polyunsaturated fatty acid (n-3 PUFAs) feed have the same effect on the level of DHA and the level of DHA in phospholipids. Methods Female C57BL / 6J mice aged 3 to 4 weeks were selected and fed with n-3PUFAs (rich in DHA), linseed oil n-3PUFAs [rich in linolenic acid] and n-3PUFAs Seed oil) feed for 12 weeks. The ratio of n-3 / n-6PUFAs in the two n-3 PUFAs was 1: 1 and n-6PUFAs was derived from sunflower oil. Four kinds of phosphatidylinositol [phosphatidylserine (PS), phosphatidylethanolamine (PE), phosphatidylinositol (PI) and phosphatidylcholine (PC)] were isolated by thin-layer chromatography and analyzed by methyl esterification-gas chromatography Methods The fatty acids in total brain fatty acids and phospholipids were determined. Results Both n-3 PUFAs diet increased DHA levels in mice plasma and brain. Compared with the n-3 PUFAs feed group [(4.95 ± 0.15)%], the level of plasma DHA in fish oil n-3 PUFAs diet group was significantly lower than that of the n-3 PUFAs [(2.04 ± 0.43)%] (21.24 ± 0.33)% vs (22.56 ± 0.14)%], the level of arachidonic acid (AA) and the level of total n-3 PUFAs (Σn-3PUFAs) (13.23 ± 0.11)% vs (11.05 ± 0.12)%], which led to the decrease of AA / DHA ratio (0.65 ± 0.12% vs 10.28 ± 0.05% vs 9.02 ± 0.05% and total n-6 PUFAs ± 0.01vs0.54 ± 0.01) and Σn-6PUFAs / Σn-3PUFAs ratio (0.63 ± 0.01 vs0.51 ± 0.01). Fatty acid analysis of four kinds of cephalin showed no significant changes in DHA and AA in PS, PE, PI and PC of fish oil n-3PUFAs compared with n-3 PUFAs in linseed oil, but AA / DHA ratio in PE 0.63 ± 0.05vs0.52 ± 0.03) and Σn-6PUFAs / Σn-3PUFAs ratio (0.66 ± 0.10vs0.56 ± 0.05) (all P <0.05). Conclusions Dietary intake of LNA alone is not as effective at concentrating DHA as brain DHA in mice. That is, brain is more likely to utilize established DHA instead of DHA converted from its precursor LNA.