日粮高胆碱水平对宫内发育迟缓猪背最长肌糖酵解的影响

Effects of high dietary concentrations of choline on longissimus dorsi muscle glycolysis in intrauterine growth retardation pigs

[目的]研究添加高胆碱日粮对宫内发育迟缓(IUGR)猪肌肉糖酵解的作用。[方法]从正常分娩的12头母猪中选择正常初生体质量(normal birth weight,NBW)和IUGR新生仔猪各12头,所有仔猪于23日龄断奶。试验采用2×2因子设计,NBW仔猪和IUGR仔猪各分别饲喂基础日粮(正常胆碱水平,NC)与添加胆碱的试验日粮(高胆碱水平,HC),即NBW+NC、NBW+HC、IUGR+NC与IUGR+HC共4组,每组6头猪,饲养至200日龄结束,称体质量后随机选择4头屠宰。[结果]IUGR猪肌糖原含量显著低于正常初生体质量仔猪,其乳酸含量及糖酵解潜值显著升高(P<0.05),乳酸脱氢酶活性有提高的趋势(P=0.057),糖原合酶(GS)的表达量显著降低(P<0.05),葡萄糖转运载体(GLUT4)mRNA表达量有下降趋势(P=0.074),M2-型丙酮酸激酶(PKM2)mRNA及M-型6磷酸果糖激酶(PFKM)mRNA的表达量显著增加(P<0.05)。高水平胆碱有使IUGR猪肌糖原含量升高(P=0.051)、乳酸含量(P=0.091)和糖酵解潜值(P=0.074)降低的趋势;高水平胆碱促使IUGR猪肌酸激酶活性显著升高(P<0.05),GS和GLUT4 mRNA的表达量显著升高(P<0.05),而PFKM mRNA表达量有下降的趋势(P=0.087)。[结论]IUGR猪的肌肉糖酵解关键酶表达量显著升高,糖原合成能力下降,乳酸含量显著升高,添加高水平胆碱可缓解IUGR猪肌糖原的大量分解,表现为糖酵解关键酶增加,乳酸含量下降,可见胆碱对提高肉品质有积极作用。

[Objectives]To investigate the effects of dietary concentrations of choline and intrauterine growth retardation（IUGR） on muscle glycolysis of pigs.[Methods]Twelve normal body weight（NBW） piglets and twelve IUGR piglets were selected according to birth weight.At weaning（23 days of age）,both NBW and IUGR piglets were fed based diet（normal choline,NC） or high choline diet（HC）.Thus,all piglets were distributed into 4 treatments（NBW ＋ NC,NBW ＋ HC,IUGR ＋ NC and IUGR ＋ HC） × 6 piglets.[Results]The glycogen of IUGR pigs was decreased significantly（P〈0.05）,and the content of lactic acid（LC） and glycolytic potential（GP） were markedly increased in IUGR pigs（P 0.05）,while compared with NBW pigs,there was a slight increase in the activity of lactate dehydrogenase（LDH） of IUGR pigs（P = 0.057）.A tendency toward decreased glucose transporters-4（GLUT4） mRNA expression was observed in the muscle of IUGR pigs（P = 0.074）,whilst IUGR significantly decreased the glycogen synthase（GS） mRNA expression,and increased pyruvate kinase M2（PKM2）,phosphofructokinase M（PFKM） mRNA expression in muscle compared to NBW（P 0.05）.Consumption of the choline diet had a trend to increase muscle glycogen of pigs（P =0.051）,and also a tend to decrease the content of LC（P = 0.091） and GP（P = 0.074）,CK activity was significantly increased after choline treatment（P〈0.05）,and there was a significant increase in GS mRNA and GLUT4 mRNA expression（P〈0.05）,but a slight decrease in PFKM mRNA expression fed by dietary choline（P = 0.087）.[Conclusions]IUGR could decrease glycogen synthesis,as well as increase the content of lactic acid by increasing the key enzyme of glycolytic expression,while high concentrations of choline have a positive way to relieve glycogen decomposition,by the increasing trend of the key enzyme of glycolysis and declined levels of lactic.