不同蛋白水平饲粮对肉兔骨骼肌发育及相关因子表达的影响

Effect of dietary protein on muscle development and relative factors of rabbit

体况相近的断奶伊拉肉兔30只,随机分为3组:高蛋白饲粮组(HPD)、中蛋白饲粮组(MPD)和低蛋白饲粮组(LPD),每组10个重复,每个重复1只兔。结果显示:随着饲粮中蛋白含量的增加,家兔的体质量、胴体质量、前腿质量、后腿质量、前腿质量/体质量和后腿质量/体质量显著增加(P<0.05);与MPD比,HPD显著增加血浆中总蛋白、尿素和胰岛素的含量(P<0.05);与MPD和LPD相比,HPD组家兔显著增加了骨骼肌中胰岛素样生长因子1(IGF1)、IGF1R、肌原性决定因子(MYOD)、肌原因子5(MYF5)、肌生成抑制蛋白(MSTN)、MYF5和包WW包含体E3泛素蛋白酶体连接酶1(WWP)的mRNA水平(P<0.05)。从整体上看,饲粮中蛋白水平能显著影响家兔骨骼肌发育。高蛋白饲粮促进骨骼肌发育可能与IGF1、MYOD和MYF5基因有关;低蛋白饲粮抑制骨骼肌发育可能与IGF1的低表达有关。

The experiment was conducted to investigate the regulation of dietary protein on muscle development and relative factors in rabbit. Thirty weaning rabbits （IRA） with similar weight were randomly divided into 3 groups with 10 repetitions of 1 rabbit each.fed high protein diet （tlPD）, fed middle protein diet （MPD） or fed low protein diet （LPD）. The trial lasted for 7 days for adaptation,and 35 days for sampling. The results show that the body weight gain,carcass weight,foreleg weight, hind legs weight, foreleg weight/body weight and hind legs weight/body weight were significantly increased with the increasing of dietary protein （P〈0.05）. Compared with the MPD, HPD significantly increased the total protein, urea, and insulin level in plasma （P 〈 0. 05）. The mRNA level of insulin-like growth factor 1 （IGF1）, IGF1R, myostatin （MSTN）, myogenic deter- mining factor （MYOD）,myogenic factor 5 （MYFS） and WW domain containing Eg ubiquitin protein ligase 1 （WWP1） were decreased in HPD compared with the MPD and LPD （P〈0.05）. The results suggest that high protein diet can affect the muscle development of rabbit. HPD can increased muscle development, which is associate with the high expression of IGF1, MYOD and MYF5. But LPD can inhibit muscle development,which might be relative to the repression of IGF1 expression.