Abstract:

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 more
could 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 PPARγ
and 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.

Key words: RS4-type resistant starch, Schizothorax prenanti Tchang, real-time PCR (RT-PCR), peroxisome proliferators activated receptors-&gamma, (PPARγ), peroxisome proliferators activated receptor &gamma, coactivator-1&alpha, (PGC-1α)