Abrahamsson Pernilla, Winsö Ola
Department of Surgical and Perioperative Sciences, Anesthesiology and Intensive Care, Umeå University Hospital, Umeå, Sweden.
J Pharm Biomed Anal. 2005 Sep 15;39(3-4):730-4. doi: 10.1016/j.jpba.2005.04.036.
To improve the reliability of microdialysis measurements of tissue concentrations of metabolic substances, this study was designed to test both the performance and the internal validity of the microdialysis methods in the hands of our research group. The stability of the CMA 600 analyser was tested with a known glucose solution in 72 standard microvials and in 48 plastic vials. To evaluate if variation in sampling time makes any difference in sample concentration (recovery), sampling times of 10, 20 and 30 min were compared in vitro with a constant flow rate of 1 microl/min. For testing of sampling times at different flow rates, an in vitro study was performed in which a constant sample volume of 10 microl was obtained. With the no net flux method, the actual concentration of glucose and urea in subcutaneous tissue was measured. The CMA 600 glucose analysis function was accurate and stable with a coefficient of variability (CV) of 0.2-0.55%. There was no difference in recovery for the CMA 60 catheter for glucose when sampling times were varied. Higher flow rates resulted in decreased recovery. Subcutaneous tissue concentrations of glucose and urea were 4.4 mmol/l and 4.1 mmol/l, respectively. To conclude, this work describes an internal validation of our use of the microdialysis system by calibration of vials and catheters. Internal validation is necessary in order to be certain of adequate sampling times, flow rates and sampling volumes. With this in mind, the microdialysis technique is useful and appropriate for in vivo studies on tissue metabolism.
为提高代谢物质组织浓度微透析测量的可靠性，本研究旨在测试我们研究团队所使用的微透析方法的性能和内部有效性。使用已知葡萄糖溶液在72个标准微量瓶和48个塑料瓶中测试了CMA 600分析仪的稳定性。为评估采样时间的变化是否会对样品浓度（回收率）产生影响，在体外以1微升/分钟的恒定流速比较了10、20和30分钟的采样时间。为测试不同流速下的采样时间，进行了一项体外研究，其中获得了10微升的恒定样品体积。采用无净通量法测量皮下组织中葡萄糖和尿素的实际浓度。CMA 600葡萄糖分析功能准确且稳定，变异系数（CV）为0.2 - 0.55%。当采样时间变化时，CMA 60导管对葡萄糖的回收率没有差异。较高的流速导致回收率降低。皮下组织中葡萄糖和尿素的浓度分别为4.4毫摩尔/升和4.1毫摩尔/升。总之，这项工作通过对微量瓶和导管的校准描述了我们对微透析系统使用的内部验证。为确定合适的采样时间、流速和采样体积，内部验证是必要的。考虑到这一点，微透析技术对于组织代谢的体内研究是有用且合适的。
