Mannheim University of Applied Sciences, Institute for Process Control and Innovative Energy Conversion (PI) and Institute for Medical Technology of the University Heidelberg and the University of Applied Sciences Mannheim, Mannheim, Germany; Mannheim Pharma and Diagnostics GmbH, Mannheim, Germany.
Freudenberg New Technologies SE, Weinheim, Germany.
Kidney Int. 2016 Dec;90(6):1377-1385. doi: 10.1016/j.kint.2016.07.024. Epub 2016 Sep 21.
Transcutaneous measurement of the glomerular filtration rate (GFR) is now frequently used in animal studies. GFR allows consecutive measurements on the same animal, including multiple measurements on a daily basis, because no blood sampling is required. Here we derive and validate a novel kinetic model for the description of transcutaneously measured FITC-Sinistrin excretion kinetics. In contrast to standard 1- to 3-compartment models, our model covers the complete kinetic, including injection and distribution of the tracer in the plasma compartment. Because the model describes the complete progression of the measurement, it allows further refinement by correcting for baseline shifts observed occasionally during measurement. Possible reasons for shifts in the background signal include photo bleaching of the skin, autofluorescence, changes of physiological state of the animals during the measurements, or effects arising from the attachment of the measurement device. Using the new 3-compartment kinetic model with modulated baseline (GFR), GFR measurements in rats can reach comparable precision as those from GFR measurements assessed using a gold standard technique based on constant infusion of a tracer. Moreover, the variability of simultaneous (parallel) measurements, as well as repeated GFR measurements in the same animals, showed higher precision when GFR was compared with the 1-compartment GFR model.
经皮肾小球滤过率（GFR）的测量现在在动物研究中经常使用。GFR 允许在同一只动物上进行连续测量，包括每天进行多次测量，因为不需要采血。在这里，我们推导出并验证了一种新的动力学模型，用于描述经皮测量的 FITC-Sinistrin 排泄动力学。与标准的 1-3 compartment 模型不同，我们的模型涵盖了完整的动力学，包括示踪剂在血浆隔室中的注射和分布。由于该模型描述了测量的完整过程，因此可以通过校正测量过程中偶尔观察到的基线偏移进一步改进。背景信号偏移的可能原因包括皮肤的光漂白、自发荧光、动物在测量过程中生理状态的变化，或来自测量设备附着的影响。使用带有调制基线的新 3 compartment 动力学模型（GFR），大鼠的 GFR 测量可以达到与基于示踪剂恒速输注的金标准技术评估的 GFR 测量相当的精度。此外，当与 1 compartment GFR 模型相比时，同时（平行）测量的变异性以及同一动物中重复的 GFR 测量显示出更高的精度。
