Establishing Standards for Studying Renal Function in Mice through Measurements of Body Size-Adjusted Creatinine and Urea Levels

Abstract

Strategies for obtaining reliable results are increasingly implemented in order to reduce errors in the analysis of human and veterinary samples; however, further data are required for murine samples. Here, we determined an average factor from the murine body surface area for the calculation of biochemical renal parameters, assessed the effects of storage and freeze-thawing of C57BL/6 mouse samples on plasmatic and urinary urea, and evaluated the effects of using two different urea-measurement techniques. After obtaining 24 h urine samples, blood was collected, and body weight and length were established. The samples were evaluated after collection or stored at −20°C and −70°C. At different time points (0, 4, and 90 days), these samples were thawed, the creatinine and/or urea concentrations were analyzed, and samples were restored at these temperatures for further measurements. We show that creatinine clearance measurements should be adjusted according to the body surface area, which was calculated based on the weight and length of the animal. Repeated freeze-thawing cycles negatively affected the urea concentration; the urea concentration was more reproducible when using the modified Berthelot reaction rather than the ultraviolet method. Our findings will facilitate standardization and optimization of methodology as well as understanding of renal and other biochemical data obtained from mice.

Diffusion‐weighted imaging of hyperpolarized [13C]urea in mouse liver

“…Although the consequences of this concentration increase have not been studied, we did not observe any toxicity effects after injection. A moderate transient increase in the urea concentration probably does not produce any adverse effects, since the normal physiologic urea concentration in mouse blood has been reported to range between 8.5 and 15 mM, 50–90 mg/dl …”

“…In our experiments, the estimated average concentration of injected HP [ 13 C, 15 N]urea was ∼8.2 mM (assuming dilution into a total blood volume of 1.7 mL for every 20 g of body weight) . The injection of exogenous urea, added to the endogenous urea, approximately doubles the normal plasma urea concentration . Although the consequences of this concentration increase have not been studied, we did not observe any toxicity effects after injection.…”

“…A moderate transient increase in the urea concentration probably does not produce any adverse effects, since the normal physiologic urea concentration in mouse blood has been reported to range between 8.5 and 15 mM, 50-90 mg/dl. 29 Although the net transport of urea is expected to remain from the intracellular space to the extracellular space, over time labeled urea can be expected to exchange into the intracellular pool. 30 However, the unexpectedly high measured ADC of urea suggests that a significant portion of urea possibly remains extracellular on the time scale of our experiment (ie, 20 sec after injection).…”

Nickel oxide-deposited cellulose/CNT composite electrode for non-enzymatic urea detection

“…Monitoring the level of biologically important molecules, such as urea, glucose, creatinine, and dopamine, in the human body is a vital issue in biochemical and medical diagnostics [1][2][3]. Various types of biosensors, including enzymatic biosensors, have been used intensively in the detection of such molecules owing to its selectivity, simplicity, and reliability [4][5][6][7].…”

Pengaruh Ekstrak Biji Anggur (Vitis Vinifera) Var Alphonso Lavallee Terhadap Fungsi Ginjal Mencit Jantan (Mus Musculus) Model Hiperurisemia

“…Kreatinin merupakan parameter yang sering digunakan untuk menilai fungsi ginjal dimana hasil metabolit kreatin ini secara bebas difiltrasi oleh glomerulus (Rodrigues WF, 2014).…”