Plasma 1,5-anhydroglucitol level as a marker of glycemic control in diabetes mellitus.

1,5-无氢葡萄糖醇（AG）是一种结构类似葡萄糖的六碳单糖，是人血清中的主要多元醇之一。血液中低浓度的ag已被证明与糖尿病有关。然而，由于测量方法的困难，人们对其代谢和动力学知之甚少。在本研究中，我们证明血浆AG的减少主要是由于尿中AG的排泄加速，这与大鼠体内葡萄糖的排泄一致。另一方面，根据测定方法的改革，我们测量了大量的人体样品，并阐明了血浆AG的动力学。血浆AG的降低程度与尿中AG的排泄量有很好的相关性，尿中AG的排泄量反映了尿中葡萄糖的排泄量，而与引起大鼠血糖的药物种类无关。我们还证明，尽管AG在体内分布广泛，但其摄取和分解代谢并不十分活跃。肾小管葡萄糖抑制AG的重吸收。因此，血浆AG的降低似乎密切反映了血糖的程度。在人体研究中，我们证实血浆AG浓度在糖尿病患者中有特异性降低。血浆AG水平受内分泌功能、肝功能、肾功能、体重、性别、年龄等因素影响较小。本文讨论了血浆AG测定的临床意义。

1,5-Anhydroglucitol(AG) is a six-carbon monosaccharide with a structure resembling that of glucose, and one of the main polyols in human serum. A low ag concentration in blood has been shown to be associated with diabetes mellitus.However, little has been known about its metabolism and kinetics partially because of the difficulties in methods of measurement. In this study, we demonstrated that the reduction of plasma AG is mainly due to the accelerated urinary excretion of AG which is coincident with the excretion of glucose in rats. On the other hand, according to the reform of assay methods, we have measured a lot of human samples and elucidated the kinetics of plasma AG.The degree of the reduction of plasma AG was well correlated with the amount of urinary excretion of AG, and the latter reflected the amount of urinary excretion of glucose irrespective of the kind of agent causing the glucosuria in rats. We also demonstrated that the uptake and catabolism of AG were not very active despite of its all-around distribution in the body. The reabsorption of AG was inhibited by glucose in renal tubule. Thus, the reduction of plasma AG seemed to reflect closely the extent of the glucosuria. In human study, we confirmed that the concentration of plasma AG showed a specific reduction in diabetes mellitus. The level of plasma AG was little affected by various factors, such as endocrine function, liver dysfunction, renal dysfunction, body mass, sex or age. The clinical significance of measurement of plasma AG are discussed in this report.