Division of Nephrology, Department of Medicine, Indiana University School of Medicine, Indiana Center for Biological Microscopy, Indianapolis, Indiana 46202, USA.
Kidney Int. 2012 Jan;81(1):112-7. doi: 10.1038/ki.2011.294. Epub 2011 Aug 31.
Measurement of the glomerular filtration rate (GFR) is the gold standard for precise assessment of kidney function. A rapid, point-of-care determination of the GFR may provide advantages in the clinical setting over currently available assays. Here we demonstrate a proof of principle for such an approach in a pig and dogs, two species that approximate the vascular access and GFR results expected in humans. In both animal models, a sub-millimeter optical fiber that delivered excitation light and collected fluorescent emissions was inserted into a peripheral vein (dog) or central venous access (pig) by means of commercial intravenous catheters. A mixture of fluorescent chimeras of a small freely filterable reporter and large non-filterable plasma volume marker were infused as a bolus, excited by light-emitting diodes, and the in vivo signals detected and quantified by photomultiplier tubes in both species in less than 60 min. Concurrent standardized 6-h iohexol plasma kidney clearances validated the accuracy of our results for both physiologic and a chronic kidney disease setting. Thus, our ratiometric technique allows for both measurement of plasma vascular volume and highly accurate real-time GFR determinations, enabling clinical decision making in real time.
肾小球滤过率（GFR）的测量是精确评估肾功能的金标准。与目前可用的检测方法相比，快速、即时的 GFR 测定在临床环境中可能具有优势。在这里，我们在猪和狗这两种在血管通路和 GFR 结果上与人类接近的物种中，证明了这种方法的原理。在这两种动物模型中，通过商业静脉导管将一根输送激发光并收集荧光发射的亚毫米光纤插入外周静脉（狗）或中心静脉通路（猪）。将小分子可自由滤过的报告分子的荧光嵌合体与大的不可滤过的血浆体积标记物的混合物作为一个弹丸注入，用发光二极管激发，然后在两种物种中通过光电倍增管检测和定量体内信号，不到 60 分钟即可完成。同时进行的 6 小时碘海醇血浆肾清除率验证了我们在生理和慢性肾病环境下的结果的准确性。因此，我们的比率技术既可以测量血浆血管容积，又可以进行高度准确的实时 GFR 测定，实现实时临床决策。
