Metabonomics with super(1)H-NMR spectroscopy and liquid chromatography-mass spectrometry applied to the investigation of metabolic changes caused by gentamicin-induced nephrotoxicity in the rat

• Published in: Biomarkers 2005-06, Vol.10 (2-3), p.173-187
• Main Authors: Lenz, E M, Bright, J, Knight, R, Westwood, FR, Davies, D, Major, H, Wilson, I D
• Format: Article
• Language: English
• ISSN: 1354-750X
• DOI: 10.1080/13547500500094034

The model nephrotoxin gentamicin was administered to male Wistar-derived rats daily, for 7 days, at 60 mg kg super(-1) day super(-1), subcutaneously, twice daily. Conventional clinical chemistry urinalysis showed a significant increase in N-acetyl- beta -D-glucosaminidase (NAG) activity from day 3. At necropsy on day 9, clear histological damage to the kidney was noted with all animals showing a generally severe nephropathy primarily focused on the proximal convoluted tubules. The urinary excretion pattern of endogenous metabolites over the time course of the study was studied using a combination of super(1)H-NMR spectroscopy and HPLC-TOF-MS/MS using electrospray ionization (ESI). Changes in the pattern of endogenous metabolites as a result of daily administration of gentamicin were readily detected by both techniques with significant perturbations of the urinary profile observed from day 7 onwards. The findings by super(1)H-NMR included raised glucose and reduced trimethylamine N-oxide (TMAO). Changes in metabonomic profiles were observed by HPLC-MS in both positive and negative ESI. The MS data showed reduced xanthurenic acid and kynurenic acid, whilst neutral loss experiments also revealed a changed pattern of sulphate conjugation on gentamicin administration.