Abstract:

Objective: To explore the effect of RS4-type resistant starch on growth performance, lipid metabolism andrelated gene expression in Schizothorax prenanti Tchang. Methods: Schizothorax prenanti Tchang weighed about 75 g wererandomly divided into five groups which were fed RS4-type resistant starch at doses of 0 (control), 3.5%, 7%, 14% and 28%,respectively. After 60 days of administration, the growth performance and serum lipid levels were measured; meanwhile,peroxisome proliferators activated receptors-alpha (PPARα) and fatty acid-binding protein (FABP mRNA) expressionlevels in muscle and liver were determined by RT-PCR. Results: The body weight, feed intake and specific growth ratio ofSchizothorax prenanti Tchang were significantly higher in the 7% and the 14% resistant starch groups than in the controlgroup (P ＜ 0.05). Feed intake was significantly increased at the dose of 28%, but neither body weight nor specific growthratio was significantly affected. The 14% resistant starch group showed significant reduced levels of blood lipids and heartfattyacid-binding protein (H-FABP) mRNA expression when compared to the control group, and a positive correlationexisted between H-FABP mRNA expression and intramuscular fat (IMF) content. When the dose was as high as 7% orabove, we observed a significant increase in PPARα mRNA expression levels in muscle and liver but a significant decreasein FABP mRNA expression level in liver. Conclusion: Dietary supplementation with the appropriate amount of RS4-typeresistant starch can promote the growth of Schizothorax prenanti Tchang, regulate lipid metabolism-related genes, andreduce the accumulation of mesenteric fat and intramuscular fat.

Key words: RS4-type resistant starch, Schizothorax prenanti Tchang, real time fluorescence quantitative polymerase chainreaction (RT-PCR), peroxisome proliferators activated receptors-alpha (PPARα), fatty acid-binding protein (FABP)