亚麻籽木脂素对雄性大鼠肌肉生长的促进作用及机制探讨

Effects of Flaxseed Lignans on the Growth of Skeletal Muscle of Male Rats and Its Possible Mechanism

【目的】以大豆黄酮为对照,研究亚麻籽木脂素对雄性大鼠骨骼肌生长的影响并探讨其作用机制。【方法】在SD雄性大鼠基础日粮中分别添加大豆黄酮(5mg·kg-1)和亚麻籽木脂素(50mg·kg-1),利用高压液相色谱、放射免疫分析、RT-PCR等方法,分析大鼠血清中亚麻籽木脂素及两种主要代谢产物(肠内酯、肠二醇)浓度、睾酮及生长激素含量、比目鱼肌和下丘脑中ER β mRNA的相对表达量。【结果】亚麻籽木脂素与大豆黄酮均能显著提高雄性大鼠饲料利用率,促进大腿肌肉增重,提高腿肌中RNA/DNA的比值,促进下丘脑和比目鱼肌中ER β mRNA表达量显著上升,使大鼠血清中睾酮含量增加,极显著性降低血清中尿素氮含量。【结论】亚麻籽木脂素可能通过与ER β结合,作用于下丘脑-垂体-性腺轴,调节大鼠血清中睾酮水平,抑制蛋白质分解,促进骨骼肌卫星细胞与肌细胞的融合,从而促进骨骼肌生长。

[Objective] To determine whether flaxseed lignans could affect the growth of skeletal muscle in male animals and its possible mechanisms. [Method] The effect of the flaxseed lignans on skeletal muscle in male rats were determined in vivo. Daidzein （5 mg·kg^-1） and flaxseed lignans （50 mg·kg^-1） were added into the basal diets, respectively, and the concentrations of the serum lignans and daidzein were measured by HPLC, serum growth hormone and testosterone （T） levels were analyzed by RIA, and the expression of estrogen receptor β （ERβ） in the soleus muscle and hypothalamus were determined by RT-PCR. [ Result ] Flaxseed lignans and daidzein significantly improved the feed efficiency and increased the total weight gain of the femoral muscle in male rats The rate of RNA to DNA in muscles and serum T levels were remarkably increased, while the urea nitrogen concentrations were significantly decreased by daidzein and flaxseed lignan and/or its metabolites. Meanwhile the expression of estrogen receptorβ （ERβ） in soleus muscle and hypothalamus were both upgraded by the two phytoestrogens. [Conclusion ] Flaxseed lignan promoted the growth of male rats, and it may regulate serum T levels through binding to ER β in hypothalamus. In turn, it depressed the catabolism of protein and promoted the hypertrophy of skeletal muscle cells.