García-Salguero L, Lupiánez J A
Departamento de Bioquímica y Biología Molecular, Facultad de Ciencias, Universidad de Granada, Spain.
Mol Cell Biochem. 1989 Jan 23;85(1):91-100. doi: 10.1007/BF00223518.
The effects of a high carbohydrate diet on the renal gluconeogenic and glycolytic capacities and on the activities of the main enzymes of the carbohydrate metabolism, fructose 1,6-bisphosphatase, phosphofructokinase and pyruvate kinase have been studied. These parameters have been analysed in two separate and isolated fractions of the renal tubule, the proximal convoluted (PCT) and the distal convoluted (DCT) zones. The results presented in this study show a rapid adaptation capacity of the kidney in response to the high amount of dietary carbohydrate, which are characterized by a decrease in the glucose production and fructose 1,6-bisphosphatase activity in the proximal tubules, and an increase in the glycolytic flux and phosphofructokinase and pyruvate kinase activities in the distal tubules. The changes in these enzyme activities took place only at subsaturating substrate concentrations and not at maximum velocity which suggest that they are probably due to an allosteric and/or covalent modifications and so, they are independent of variations in the cellular levels of the enzymes.
研究了高碳水化合物饮食对肾脏糖异生和糖酵解能力以及碳水化合物代谢主要酶（果糖1,6 - 二磷酸酶、磷酸果糖激酶和丙酮酸激酶）活性的影响。这些参数在肾小管的两个独立且分离的部分，即近端曲管（PCT）和远端曲管（DCT）区域进行了分析。本研究呈现的结果表明，肾脏对高碳水化合物饮食具有快速适应能力，其特征是近端小管中葡萄糖生成和果糖1,6 - 二磷酸酶活性降低，而远端小管中糖酵解通量以及磷酸果糖激酶和丙酮酸激酶活性增加。这些酶活性的变化仅在底物浓度不饱和时发生，而非在最大速度时发生，这表明它们可能是由于变构和/或共价修饰引起的，因此，它们与酶的细胞水平变化无关。
