Clinical chemistry analyzer

The clinically recommended doses of zidovudine and amikacin are 6 mg/kg/day and 15 mg/kg/day, respectively. The rationale for selecting zidovudine and amikacin doses was based on the recommended corresponding surface area dosage conversion factor (48 (link)). Therefore, the dosages of zidovudine and amikacin in the rats were 40 mg/kg and 100 mg/kg once daily, respectively.
Blood samples were taken from the tail of each rat at baseline and each day prior to dosing to determine serum creatinine levels. The samples were allowed to clot and centrifuged at 11,000 rpm for 15 min; then, the serum was drawn off and stored at −80°C until analysis. Serum creatinine level was analyzed with a clinical chemistry analyzer (Roche Pharmaceutical Ltd., Basel, Switzerland). Nephrotoxicity was defined as the doubling of the baseline creatinine level (49 (link)).
To determine the concentrations of zidovudine and amikacin in TCF, samples were taken from each rat at several time points (0, 0.5, 1,2, 4, 8, 12, and 24 h) on the last day of therapy. The samples were immediately centrifuged at 10,000 rpm for 10 min and then stored at −80°C until analysis. The concentrations of zidovudine and amikacin were analyzed through high-performance liquid chromatography and liquid chromatography-tandem mass spectrometry as previously described (50 (link), 51 (link)).

The serum levels of blood urea nitrogen (BUN), creatinine, and cystatin C were detected to evaluate renal function. A clinical chemistry analyzer (Roche, Rotkreuz, Switzerland) was used to detect the levels of serum creatinine and BUN. Cystatin C levels were measured in each mouse using a competitive ELISA kit (catalog #: E-90CYS; ICL Lab, Portland, OR, USA), which the absorbance at 450 nm was detected. Serum AGEs levels were also determined by competitive ELISA assay (catalog #: STA-817; Cell Biolabs, San Diego, CA, USA), during which the absorbance at 450 nm was detected.

A commercially available clinical chemistry analyzer (Roche, Rotkreuz, Switzerland) was used to measure the serum albumin, globulin, creatinine, and blood urea nitrogen (BUN) levels. A mouse ELISA kit (Immunology Consultants Laboratory, Portland, OR, USA) was used to detect the levels of cystatin C. Serum fibroblast growth factor (FGF)-23 was determined using a mouse FGF23 ELISA kit (Abcam, Cambridge, MA, USA).