Strindberg L, Lönnroth P
Department of Internal Medicine, Sahlgrenska University Hospital, Göteborg, Sweden.
Scand J Clin Lab Invest. 2000 May;60(3):205-11. doi: 10.1080/003655100750044857.
In order to validate the use of urea as an internal reference for the calibration of microdialysis catheters, both subcutaneous and muscle measurements were taken in 11 healthy volunteers. The equilibration calibration of urea, glucose and lactate, and the internal reference (3H-glycerol retrodialysis) calibration of glycerol were performed in both the muscle and fat. These data were then compared with those taken from the arterial plasma. Based on the average arterial-interstitial fluid concentration difference, the urea microdialysis relative recovery was estimated from dialysate and plasma content of urea. Interstitial urea was then used as an endogenous reference for the calculation of the relative recovery of each substance. This was carried out after defining the relative recovery ratios (RR) that were obtained from in vitro measurements on crystalline solutions with the assumption that RR in vivo = RR in vitro. The data demonstrate that the interstitial fluid concentrations of glucose, lactate and glycerol can be calculated from the knowledge of plasma and microdialysate content of urea together with the RR in vitro. Also, the data that were obtained using urea as an endogenous reference showed a significant correlation with those that were achieved using either equilibration or internal reference (retrodialysis) techniques for calibrating the microdialysis devices.
为了验证将尿素用作微透析导管校准的内部参考物的可行性，对11名健康志愿者进行了皮下和肌肉测量。在肌肉和脂肪中均进行了尿素、葡萄糖和乳酸的平衡校准以及甘油的内部参考（³H-甘油反向透析）校准。然后将这些数据与从动脉血浆中获取的数据进行比较。根据平均动脉-组织间液浓度差，从透析液和血浆中的尿素含量估算尿素微透析相对回收率。然后将组织间液尿素用作计算每种物质相对回收率的内源性参考物。这是在定义了从晶体溶液的体外测量中获得的相对回收率（RR）之后进行的，假设体内RR =体外RR。数据表明，葡萄糖、乳酸和甘油的组织间液浓度可以根据血浆和微透析液中的尿素含量以及体外RR来计算。此外，使用尿素作为内源性参考物获得的数据与使用平衡或内部参考（反向透析）技术校准微透析设备所获得的数据具有显著相关性。
