Abstract: Objective To investigate the effects of n-3 polyunsaturated fatty acids (n-3 PUFAs) during maternal pregnancy and lactation on expression of brain-derived neurotrophic factor (bdnf) in offspring. Methods Forty 6~8 week-old C57BL/6J female mice were randomly divided into 5 groups,and fed with the n-3 PUFA deficient diet,and four n-3 PUFAs diets with different ratios of n-6/n-3 PUFAs at 15∶1,5∶1,1∶1 and 1∶5 respectively.Followed by 6 weeks feeding,the mice were mated for breeding pups,who received the same diets with their mothers.At postnatal 7,21 d and 3 months respectively,pups were sacrificed and the brain were used for detecting bdnf expression.Equal pups from groups of n-3 PUFA deficient diet and n-6/n-3 PUFAs (5∶1) diet were selected and diets were changed each other at postnatal 21 d lasting for 3 months.The mRNA expressions of bdnf in the brain cortex were measured by real-time RT-PCR. Results Compared to n-3 PUFAs deficient diet group,at both postnatal 7 d and 21 d,the increased bdnf mRNA expression was only seen in the n-6/n-3 PUFAs (1∶5) diet group;at 3 months,all the diets containing n-3 PUFAS had increased bdnf mRNA level.Feeding with the n-6/n-3 PUFAs (5∶1) diet to pups from the n-3 deficient diet group did not increase bdnf mRNA expression,whereas feeding with the n-3 PUFA deficient diet to pups from the n-6/n-3 PUFAs (5∶1) diet group increased bdnf expression. Conclusion Higher dietary intake of n-3 PUFAs during maternal pregnancy and lactation may be needed for optimal expression of bdnf gene.The appropriate n-3 PUFA intake may be beneficial in keeping bdnf expression normal in adult.

Key words: n-3 polyunsaturated fatty acids, brain-derived neurotrophic factor, brain development, early nutrition, mouse

摘要： 目的 探讨孕期及哺乳期n-3 多不饱和脂肪酸(n-3 polyunsaturated fatty acids,n-3 PUFAs)摄入量及其与n-6 PUFAs比例对仔鼠脑源性神经营养因子(brain-derived neurotrophic factor,bdnf)基因表达的影响。方法 使用6~8周龄清洁级C57BL/6J雌性小鼠,随机分为5 组,分别给予n-3 PUFAs缺乏和4种不同含量n-3 PUFAs(n-6/n-3 PUFAs比值分别为15∶1、5∶1、1∶1及1∶5)饲料喂养。小鼠12~14周龄时雌雄合笼交配繁殖,仔鼠断乳后继续行母鼠相同饲料喂养,分别在生后7 d、21 d和3 月时被处死后取脑。同时,分别从n-3 PUFAs缺乏组和n-6/n-3 PUFAs(5∶1)组中选取等量仔鼠,21 d断乳后相互交换饲料喂养至3个月,处死后取脑。采用实时荧光定量PCR技术测定脑皮质bdnf基因mRNA的表达。结果 与n-3 PUFAs缺乏饲料组相比,对于7 d和21 d幼年仔鼠,只有n-6/n-3 PUFAs(1∶5)饲料组bdnf基因mRNA表达量显著升高;对于3 月龄成年仔鼠,各含n-3 PUFAs饲料组bdnf基因mRNA的表达均升高。对于孕期和哺乳期n-3 PUFAs缺乏饲料组仔鼠,断乳后给予含n-3 PUFAs饲料喂养未能提升脑皮质bdnf基因mRNA表达;而孕期和哺乳期含n-3 PUFAs饲料喂养的仔鼠,断乳后给予n-3 PUFAs缺乏饲料喂养时,脑皮质bdnf基因mRNA表达量见一定程度的升高。结论 孕期及哺乳期可能需要较高的n-3 PUFAs摄入,才能满足幼年期诱导脑bdnf表达之需。保证生命早期n-3 PUFAs的适量摄入,有助于维持成年期bdnf的正常表达。

关键词: n-3 多不饱和脂肪酸, 脑源性神经营养因子, 脑发育, 早期营养, 小鼠