We evaluated the effect of glucose injection on and glycolytic enzymes in GIFT (=150, mean weight 80±5 g) wererandomly assigned to one of two groups, a control group that was injected with sterile 0.7% saline and a treatment group that was injected intraperitoneally with glucose (30 mg/100 g wet weight). The fish in both groups were euthanized 1–12 h after injection. Glucose injection resulted in hyperglycemia with maximum glucose levels observed 1 h after injection (<0.05) and a return to normal levels after 3 h. Cholesterol content also increased significantly (<0.05) after glucose injection. Conversely, triglycerides, glutamic-pyruvic transaminase (GPT) levels were unaffected by glucose injection. The level of glutamic-oxalacetic transaminase (GOT) decreased significantly (<0.05) after injection. Liver glycogen peaked 6 h after injection with glucose, then decreased significantly (<0.05). Glucose injection had no effect on muscle glycogen levels. Insulin levels increased significantly (<0.05) in the plasma and muscle, but not in the liver, following glucose injection. Pyruvate kinase levels peaked 6 h after glucose injection (<0.05). Conversely, there was no change in hexokinase activity after injection. Our results suggest that metabolic adjustment caused by glucose administration is reflective of the regulatory action of insulin and pyruvate kinase. The levels of insulin and pyruvate kinase (PK) were unable to maintain pace with the absorption speed of carbohydrates in fish and a shortage in hexokinase (HK) activity limited glucose utilization, leading to higher concentrations of cholesterol.