Metabonomics with 1H-NMR spectroscopy and liquid chromatography-mass spectrometry applied to the investigation of metabolic changes caused by gentamicin-induced nephrotoxicity in the rat.
The model nephrotoxin gentamicin was administered to male Wistar-derived rats daily, for 7 days, at 60 mg kg-1 day-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 1H-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 1H-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.
Lenz
E M
EM
Department of Drug Metabolism and Pharmacokinetics, AstraZeneca, Macclesfield, UK.
Bright
J
J
Knight
R
R
Westwood
F R
FR
Davies
D
D
Major
H
H
Wilson
I D
ID
D000118:Acetylglucosaminidase / Q000652:urine; D000818:Animals; D015415:Biomarkers; D002851:Chromatography, High Pressure Liquid; D018360:Crystallography, X-Ray; D003627:Data Interpretation, Statistical; D005839:Gentamicins; D006029:Glycosuria / Q000378:metabolism; D007668:Kidney / Q000473:pathology; D007674:Kidney Diseases / Q000139:chemically induced* / Q000378:metabolism* / Q000473:pathology; D007770:L-Lactate Dehydrogenase / Q000652:urine; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D011500:Protein Synthesis Inhibitors; D051381:Rats; D017208:Rats, Wistar; D021241:Spectrometry, Mass, Electrospray Ionization
D015415:Biomarkers; D005839:Gentamicins; D011500:Protein Synthesis Inhibitors; D007770:L-Lactate Dehydrogenase; D000118:Acetylglucosaminidase