Schmidt F J, Sluiter W J, Schoonen A J
Department of Pharmaceutical Technology and Biopharmaceutics, University Centre for Pharmacy, Groningen, The Netherlands.
Diabetes Care. 1993 May;16(5):695-700. doi: 10.2337/diacare.16.5.695.
To compare the subcutaneous glucose sensor measurements with two reference methods. Previous studies provide conflicting findings about the real glucose concentrations in subcutaneous tissue. Some suggest substantially lower concentration, whereas others measure proportionally higher glucose concentrations compared with the blood compartment. Before these results can be taken seriously as an expression of the real glucose concentration in the extracellular space, the measurements must be validated by an independent method.
We applied a microdialysis-based enzyme sensor to measure glucose concentration in subcutaneous tissue. We also developed two reference methods: subcutaneous filtrate collection and an equilibration method using ultrafiltration membranes to support the earlier findings. We provided an anatomical model to explain the results.
The mean overall intercellular filtrate glucose concentration, sampled with the filtrate collector and taken after a 6-h stabilization time, including the values during the glucose clamp period, was 46 +/- 9%. The mean subcutaneous glucose concentration measured with the glucose sensor, calibrated in vitro, was 44 +/- 8% of the mean venous blood glucose concentration. Mean overall intercellular equilibrate glucose concentration, i.e., the mean glucose concentration in the subcutaneous extracellular space, taken after a 4-h stabilization time, was 46 +/- 15% of the mean venous blood glucose concentration.
The close agreement between the mean values of subcutaneous glucose concentrations, obtained with three independent methods--filtration, equilibration, and dialysis (sensor)--shows the real glucose concentration in subcutaneous interstitial fluid is approximately 50% the blood glucose value in normal humans. Our results clarify some of the conflicting evidence presented in previous studies.
将皮下葡萄糖传感器测量结果与两种参考方法进行比较。先前的研究对于皮下组织中的实际葡萄糖浓度给出了相互矛盾的结果。一些研究表明浓度显著更低，而另一些研究则测得与血液中的葡萄糖浓度相比成比例更高的葡萄糖浓度。在这些结果能够被认真视为细胞外空间中实际葡萄糖浓度的表达之前，测量结果必须通过一种独立方法进行验证。
我们应用基于微透析的酶传感器来测量皮下组织中的葡萄糖浓度。我们还开发了两种参考方法：皮下滤液收集法和使用超滤膜的平衡法，以支持早期的研究结果。我们提供了一个解剖学模型来解释结果。
使用滤液收集器采样并在6小时稳定时间后获取的平均细胞间滤液葡萄糖浓度，包括葡萄糖钳夹期的值，为46±9%。用体外校准的葡萄糖传感器测得的皮下葡萄糖平均浓度为静脉血葡萄糖平均浓度的44±8%。平均细胞间平衡葡萄糖浓度，即皮下细胞外空间中的平均葡萄糖浓度，在4小时稳定时间后测得，为静脉血葡萄糖平均浓度的46±15%。
通过三种独立方法——过滤、平衡和透析（传感器）——获得的皮下葡萄糖浓度平均值之间的密切一致性表明，正常人体内皮下间质液中的实际葡萄糖浓度约为血糖值的50%。我们的结果澄清了先前研究中呈现的一些相互矛盾的证据。
