鱼油摄入对肥胖大鼠脂肪组织、瘦素表达和胰岛素水平的影响

目的探讨鱼油摄入对肥胖大鼠体重增量、脂肪组织、瘦素基因表达、血清瘦素及胰岛素水平的影响。方法雄性Wistar大鼠在高脂(猪油20%WT/WT)饮食8 w后,以体重比对照组重30g及以上(约1个标准差)为标准分出肥胖大鼠,并按体重随机分为两组:猪油组(猪油20/100 WT/WT)和鱼油组(鱼油20/100WT/WT),保留对照组,分别饲以相应饲料,继续饲养4w。腹腔麻醉,心脏穿刺取血并分离血清,测血清瘦素及胰岛素水平;处死大鼠,分离腹膜后、附睾脂肪组织,称湿重,做腹膜后脂肪组织切片,以目镜测微计测脂肪细胞直径;RT-PCR检测脂肪组织瘦素mRNA。结果 (1)鱼油组大鼠体重增量、腹膜后、附睾脂肪组织湿重、脂肪细胞体积显著低于猪油组;其脂肪组织瘦素mRNA表达水平、血清瘦素、胰岛素水平均有降低趋势,但未达到统计学意义上的显著差异。(2)猪油、鱼油两组大鼠血清瘦素水平与血清胰岛素水平均呈显著的相关关系。结论鱼油饮食4w能显著降低肥胖大鼠体重增量、脂肪组织含量,但未能显著降低脂肪组织瘦素mRNA水平、血清瘦素及胰岛素水平。营养学报,2013,35(2):146-149]

EFFECTS OF FISH OIL INTAKE ON ADIPOSE TISSUE, LEPTIN EXPRESSION AND INSULIN LEVEL IN OBESE RATS

Objective To investigate the effects of fish oil diet on the expression of leptin in fat tissue,and the levels of serum leptin and insulin in high-fat diet induced obese rats.Methods After fed a high-fat diet(lard,20/100 WT) for 8 w,the obese rats,30g heavier than controls,were separated and divided into two groups: lard group and fish oil group.The lard group was continuously fed high fat diet,while the fish oil group fed the same diet except that fish oil substituted for lard.After feeding for another 4 w,the blood samples were drawn for analysis.After the rats were killed,the retroperitoneal and epididymal fat masses were carefully collected and weighed.The levels of serum insulin and leptin were measured by RIA.The adipose tissue samples were fixed in 10% buffered formalin and embedded in paraffin.The tissue was sectioned(10μm) and stained with hemotoxylin and eosin,and adipocyte diameter was determined using a microscope equipped with a graduated ocular micrometer.Total RNA in retroperitoneal fat tissue was extracted and the level of leptin mRNA was evaluated by RT-PCR.Results(1) Compared to lard diet,fish diet significantly reduced weight gain,retroperitoneal and epididymal fat masses.A declining trend was also shown in the levels of leptin mRNA,serum leptin and serum insulin,but without significant difference.(2) The level of serum leptin in lard group and fish oil group was significantly related to the level of serum insulin.Conclusion Fish oil feeding for 4 w ameliorates obesity,but it does not decrease the levels of leptin expression,serum leptin and insulin significantly.ACTA NUTRIMENTA SINICA,2013,35(2):146-149]