Development of a non-invasive measurement method for 1,5AG

我们研究了1,5-无氢葡萄糖醇（1,5 ag）在汗液、唾液和泪液等体液中的浓度。我们还尝试开发了一种新的方法来测量少量的1,5 ag。现有的测定方法可检测汗液和泪液中1,5 ag的浓度，其水平约为血清水平的10 ~ 70%。试验间CV约为30%。血清与汗液1,5 ag的相关性显著（r* 0.70）。日常测量的变化相对较小。而唾液中1、SAG的测定则因伴随物的干扰而比较困难。测量需要对试样进行孔隙过滤。孔径为5000 ~ 10000 Da的压滤后，在5℃的高压下，CV值有较大提高。然而，该方法显著降低了1,5 ag的含量。需要对过滤膜进行根本性的改进，但尚未实现。唾液中ag的浓度不受食物摄入的严重影响。为了使1,5 ag的检测方法对少量的1,5 ag更加敏感，我们尝试提纯PROD酶，或改变HK、UK和PROD的比例，在这些研究中我们发现HK和UK的一些Jot(s)对1,5 ag表现出很高的亲和力。非特异性效应使得使用这些酶来测量1,5 ag极为困难。然而，一项新的研究发现，1,5ag可以与UK反应，为我们提供了许多关于1,5ag的生理作用，特别是在胰腺β细胞中的作用的信息。

We investigated the concentrations of 1,5-anhydroglucitol (1,5AG) in the fluid of the body, such as sweat, saliva and tear. We also tried to develop a new method for measuring 1,5AG in small amount.The concentrations of 1,5AG both in sweat and tear were detectable by the existing measurement method, and the level were approximately 10 to 70% that of serum level. The inter assay CV was about 30%. The correlation between serum and sweat 1,5AG was significant (r*O.7O). Variations of the measurements in day-to-day were relatively small. In contrast, the measurement of 1, SAG in saliva was difficult because of disturbance with concomitant substances. The measurement needed pore filtration of the specimens. After the pressure-filtration with pore size 5000 to 10000 Da, under 5ﾟC, the CV value was greatly improved. However, the value of 1,5AG content was markedly reduced by the method. Fundamental improvement of filtration membrane was required, but had not been achieved. 1,5AG concentration in saliva was not acutely influenced by food ingestion.To make assay method of 1,5AG more sensitive for small amount of 1,5AG, we tried to purify PROD enzime, or to change the ratio of HK, UK and PROD.During these investigation we found that some Jot(s) of HK and UK showed high affinity for 1,5AG.The non-specific effect make it extremely difficult to use these enzimes for measurement of 1,5AG.However, a new finding that 1,5AG can react with UK provided us a lot of information concerning physiological role of 1,5AG, especially inpancreatic beta-cells.