Abstract: 【Objective】 To investigate the effects of n-3 polyunsaturated fatty acids(n-3 PUFAs) on the mRNA expression of satiety regulators in diet-induced obese (DIO) mice. 【Methods】 Three to four-week-old male C57BL/6J mice were randomly divided into 3 groups with 15 cases in each group. There mice were fed with two types of high-fat diet(34.9% fat providing 60% of total energy) with n-6 PUFAs(originated from sunflower oil) and n-3 PUFAs(originated from fish oil) respectively to induce obesity, with a normal-fat diet(4.3% fat providing 10% of total energy) as lean control. After fasted for 12 hours, blood samples were drawn, and brains and epididymal fat were collected. Plasma leptin concentrations were measured by enzyme-linked immunosorbent assay. The mRNA expressions of leptin in fat and leptin receptor(leptin-R), neuropeptide Y(NPY) and proopiomelanocortin(POMC) in the hypothylamus were assayed by real-time RT-PCR. 【Results】 The body weight and plasma leptin concentration in both DIO mice were significantly increased compared to the lean control mice, however the changes in the DIO mice with the n-3 PUFA diet were much smaller than the DIO mice with the n-6 PUFA diet. As compared to the lean control mice, the mRNA expressions of leptin, leptin-R and POMC were higher and those of NPY were lower in DIO mice with the n-6 PUFA diet, whereas no changes were shown for the four genes' expression in the DIO mice with the n-3 PUFA diet. 【Conclusion】 Dietary fish oil n-3 PUFAs may play some positive roles by antagonizing the abnormal expressions of the satiety regulators in DIO mice.

Key words: n-3 polyunsaturated fatty acids, obesity, mice, leptin, neuropeptide Y, proopiomelanocortin

摘要： 【目的】 探讨n-3多不饱和脂肪酸(n-3 PUFAs)对饲料诱导肥胖小鼠食欲调节因子表达的影响。 【方法】 使用3~4周龄C57BL/6J雄性小鼠,随机分为3组,每组15只,分别给予两种高脂饲料(脂肪含量为34.9%,供能比为60%)-n-6PUFAs(来源于葵花籽油)饲料和n-3PUFAs(来源于鱼油)饲料喂养3个月;以正常脂饲料(脂肪含量为4.3%,供能比为10%)作为诱导肥胖鼠的对照。小鼠禁食12 h后,麻醉状态下心脏取血、脑和性腺周围脂肪。血浆瘦素含量测定采用酶联免疫分析法;脂肪组织瘦素及下丘脑瘦素受体、神经肽Y(NPY) 和促阿片-黑素细胞皮质素原(POMC)mRNA表达采用实时荧光定量PCR进行。 【结果】 两组高脂饲料诱导的肥胖小鼠体重和血浆瘦素浓度均高于正常脂饲料组小鼠,但n-3PUFAs高脂饲料组肥胖小鼠在两项指标的增高程度显著低于n-6PUFAs高脂饲料组肥胖小鼠。与正常脂饲料喂养小鼠相比,n-6PUFAs高脂饲料诱导肥胖小鼠脂肪组织瘦素和下丘脑瘦素受体、POMC mRNA表达水平显著升高,而NPY mRNA水平降低;n-3PUFAs高脂饲料诱导肥胖小鼠的上述4种基因mRNA表达则未发生变化。 【结论】 n-3PUFAs可减轻肥胖状态下瘦素及其受体、NPY、POMC等食欲调节因子表达的异常,在肥胖发生中起着积极作用。

关键词: n-多不胞和脂肪酸, 肥胖, 小鼠, 瘦素, 神经肽Y, 促阿片-黑素细胞皮质素原