母鼠孕期补充二十二碳六烯酸对出生幼鼠脑脂质成分的影响

Effect of supplementation with docosahexaenoic acid during pregnancy on brain fat composition of newborn rat

目的比较母鼠孕期补充二十二碳六烯酸(DHA)或α-亚麻酸(LNA)对其出生幼鼠脑中脂质成分的影响。方法24只母鼠随机平均分为3组,在孕期分别给予不同饲料喂养:对照组给予普通饲料(低脂饲料+含低LNA和DHA的普通食油),LNA组在饲料中补充LNA(100 mg/d),DHA组补充DHA(100 mg/d)。三组母鼠分娩后,在幼鼠刚出生及出生后11、21 d时,分别将幼鼠处死,分离脑组织,测定并比较各组幼鼠脑中各脂肪酸含量。结果幼鼠出生后脑中DHA的含量逐渐增加。DHA组幼鼠脑中DHA的含量显著高于对照组和LNA组(P<0.05);LNA组幼鼠脑中DHA的含量也有升高,明显高于对照组,但低于DHA组(P<0.05);新生鼠及哺乳期幼鼠脑中DHA含量与其在血浆中的含量显著相关(r分别为0.820和0.762,P<0.01)。结论母鼠孕期补充DHA后可明显增加其出生幼鼠脑中DHA的含量,补充LNA后其出生幼鼠脑中DHA含量也增加,但增加的程度没有补充DHA显著。

Objective To compare the effect of supplementation with docosahexaenoic acid （DHA） or α-linolenic acid （LNA） during pregnancy on brain fat composition of newborn rat. Methods Twenty-four pregnant rats were divided randomly into three groups： control group, with maternal rats fed with ordinary food; LNA group, with maternal rats supplemented with LNA （ 100 mg/d） ; and DHA group, with maternal rats supplemented with DHA （ 100 mg/d）. Baby rats of the three groups were sacrified at day 1, day 11 and day 21 after birth and their brain samples were obtained. Fatty acid compositions in the brain were analyzed by gas chromatography and were compared among the three groups. Results The contents of DHA and fat in the brain of newborn rats were gradually increased after birth. DHA levels in the brain of newborn rats whose mother were supplemented with DHA were significantly higher than those of the control group and LNA group （ P 〈 0.05）. DHA levels in those whose mother were supplemented with LNA were significantly higher than those of the control group, but lower than those of the DHA group（ P 〈0.05）. DHA levels in the brain of newborn rats and breast-fed young rats were well correlated with those in the blood （ r = 0. 820 and 0. 762, P 〈 0.01, respectively）. Conclusion Either supplementation with DHA or LNA to maternal rats during pregnancy can significantly increase the DHA levels in the brain of newborn rats, and the former may yield a better result.