Fukuda H, Iritani N
Biochim Biophys Acta. 1984 Aug 15;795(1):79-84. doi: 10.1016/0005-2760(84)90106-1.
When 1-, 2- and 9-month-old rats adapted to a stock diet were fed a fat-free/high-sucrose diet, the changes in the substrate and effector levels of glycolytic and lipogenic enzymes in liver, and the effects of aging on the changes were investigated. By the sucrose diet feeding, the activities of phosphofructokinase, pyruvate kinase and fructokinase were increased, whereas hexokinase activity was markedly decreased. The fructose 1-phosphate levels were significantly increased in the liver, while conversely, the glucose 6-phosphate and fructose 6-phosphate levels were decreased. As a result of sucrose diet feeding, the changed enzyme activities would appear to be consistent with the metabolic pathway for fructose being predominant over that for glucose. Consequently, the concentrations of acetyl-CoA, citrate and malate were increased and would in turn appear to favour an increase in lipogenesis. The changes in the substrate and effector levels of lipogenic enzymes were reduced with aging, as were those in the enzyme activities. However, the changes in enzyme activities and metabolite levels of glycolysis were not much affected with aging.
将适应常规饲料的1月龄、2月龄和9月龄大鼠喂以无脂/高蔗糖饲料，研究肝脏中糖酵解和脂肪生成酶的底物和效应物水平变化，以及衰老对这些变化的影响。通过喂食蔗糖饲料，磷酸果糖激酶、丙酮酸激酶和果糖激酶的活性增加，而己糖激酶活性显著降低。肝脏中磷酸果糖-1-磷酸水平显著升高，相反，葡萄糖-6-磷酸和果糖-6-磷酸水平降低。喂食蔗糖饲料的结果是，酶活性的变化似乎与果糖代谢途径占主导地位而不是葡萄糖代谢途径一致。因此，乙酰辅酶A、柠檬酸和苹果酸的浓度增加，进而似乎有利于脂肪生成增加。随着衰老，脂肪生成酶的底物和效应物水平变化以及酶活性变化均降低。然而，糖酵解的酶活性和代谢物水平变化受衰老影响不大。
