RS4型抗性淀粉对齐口裂腹鱼脂肪代谢相关酶及相关基因表达的影响

Effect of RS4-Type Resistant Starch on Lipid Metabolism-Related Enzymes and Gene Expression in Schizothorax prenanti Tchang

目的:研究RS4型抗性淀粉对齐口裂腹鱼脂肪代谢相关酶及相关基因表达的影响。方法:将体质量75g左右的齐口裂腹鱼随机按RS4型抗性淀粉添加量分为5组:0%(对照组)、3.5%、7%、14%、28%。饲喂60d,采用铜试剂法测定脂蛋白脂酶(lipoprotein lipase,LPL)、肝脂酶(hepatic lipase,HL)活性及游离脂肪酸(free fatty acids,FFA)含量,并采用实时荧光定量聚合酶链式反应(real-time-polymerase chain reaction,RT-PCR)技术检测各组肌肉及肝脏中过氧化物酶增殖体激活受体γ(peroxisome proliferators activated receptorγ,PPARγ)、过氧化物酶体增殖物激活受体γ辅助活化因子(peroxisome proliferators activated receptorγcoactivator-1α,PGC-1α)mRNA表达水平。结果:RS4型抗性淀粉添加剂量在7%以上时能够显著的提高齐口裂腹鱼肝脏中脂蛋白脂酶和肝脂酶活性(P<0.05),使血清及肝脏中游离脂肪酸含量增加(P<0.05);添加量为3.5%对LPL、HL活性及FFA含量均无显著影响(P>0.05)。添加量为7%和14%时能显著提高肌肉和肝脏中PPARγ和PGC-1αmRNA表达量(P<0.05)。结论:适当的添加RS4型抗性淀粉能提高齐口裂腹鱼肌肉和肝脏中脂肪代谢相关基因mRNA表达水平,同时也能够增加齐口裂腹鱼肝脏中脂肪代谢相关酶的活性,促进甘油三酯的分解。

Objective: To explore the effect of RS4-type resistant starch on the lipid metabolism-related enzymes and mRNA expression in Schizothorax prenanti Tchang. Methods: Schizothorax prenanti Tchang of approximately 75 g body weight were randomly divided into five groups. After 60 days of feeding, the activities of lipoprotein lipase(LPL) and hepatic lipase(HL) and free fatty acid(FFA) content were determined by copper reagent method. The mRNA expression levels of PPARγ and PGC-1α in muscle and liver were determined by RT-PCR. Results: RS4-type resistant starch at a dosage of 7% or morecould significantly improve the activities of liver LPL and HL in Schizothorax prenanti Tchang, increase free fatty acid content in the serum and liver(P < 0.05); while, RS4-type resistant starch at a dosage of 3.5% had no effect on the activities of LPL and HL or free fatty acid content(P > 0.05). In addition, the mRNA expression levels of muscle and liver PPARγand PGC-1α in the groups administered with RS4-type resistant starch at dosages of 7% and 14% were significantly higher than those in the control group(P < 0.05). Conclusion: Dietary supplementation of RS4-type resistant starch at an appropriate amount could increase the expression of lipid metabolism-related genes in muscle and liver, improve the activities of lipid metabolismrelated enzymes, and promote the breakdown of triglycerides in Schizothorax prenanti Tchang.