COMPARATIVE STUDY OF THE DIFFERENCE IN GLUCOSE AND DEXTRIN UTILIZATION IN THE CHINESE PERCH (SINIPERCA CHUATSI)

In this study, we compared the utilization of different carbohydrates in Chinese perch and further explored the molecular mechanism of carbohydrate utilization in carnivorous fish. Water, plasma, liver and muscle samples were collected at 0, 1, 2, 3, 4, 8, 12 and 24h after Chinese perch were fed glucose and dextrin at a 1670 mg/kg dose. The parameters urine sugar, blood glucose, blood triglycerides, blood insulin, and liver and muscle glycogen and the mRNA expression levels of glucose metabolism-related genes were detected. The results showed the following: (1) Within 1—12h after feeding, the blood glucose level was significantly higher in the glucose group than in the dextrin group, while the blood glucose and insulin levels were not significantly different between the two groups. (2) The triglyceride content at 2—4h was higher in the dextrin group than in the glucose group, and the liver glycogen content at 1h was significantly higher in the dextrin group than in the glucose group. Furthermore, the muscle glycogen content at 24h was significantly higher in the dextrin group than in the glucose group. (3) One hour after feeding, the mRNA expression levels of glucokinase (GK), fatty acid synthetase (FAS), acetyl-CoA carboxylase type I (ACC1) and citrate synthase (CS) were significantly higher in the dextran group than in the glucose group, and the expression levels of glycogen synthase (GS) and CS mRNA at 8h were significantly lower in the dextrin group than in the glucose group. These results demonstrated that the utilization efficiency of dextrin was better than that of dextrose and that the intake of dextrin could promote the synthesis of glycogen and fat.