A metabonomic investigation of the biochemical effects of mercuric chloride in the rat using 1H NMR and HPLC-TOF/MS: time dependant changes in the urinary profile of endogenous metabolites as a result of nephrotoxicity

Abstract

The effects of the administration of a single dose of the model nephrotoxin mercuric chloride (2.0 mg kg(-1), subcutaneous) to male Wistar-derived rats on the urinary metabolite profiles of a range of endogenous metabolites has been investigated using (1)H NMR and HPLC-MS. Urine samples were collected daily for 9 days from both dosed and control animals. Analysis of these samples revealed marked changes in the pattern of endogenous metabolites as a result of HgCl(2) toxicity. Peak disturbances in the urinary metabolite profiles were observed (using both NMR and HPLC-MS) at 3 days post dose. Thereafter the urinary metabolite profile gradually returned to a more normal composition. Markers of toxicity identified by (1)H NMR spectroscopy were raised concentrations of lactate, alanine, acetate, succinate, trimethylamine (TMA), and glucose. Reductions in the urinary excretion of citrate and alpha-ketoglutarate were also seen. Markers identified by HPLC-MS, in positive ion mode, were kynurenic acid, xanthurenic acid, pantothenic acid and 7-methylguanine which decreased after dosing. In addition an ion at m/z 188, probably 3-amino-2-naphthoic acid, was observed to increase after dosing. As well as these identified compounds other ions at m/z 297 and 267 decreased after dosing. In negative ion mode a range of sulfated compounds were observed, including phenol sulfate and benzene diol sulfate, which decreased after dosing. As well as the sulfated components an unidentified glucuronide at m/z 326 was also observed to decrease after dosing. The results of this study demonstrate the complementary nature of the NMR and MS-based techniques for metabonomic analysis.

Metabolomics as an Extension of Proteomic Analysis: Study of Acute Kidney Injury

“…Our results confirm previous studies where quantitative changes by NMR spectroscopic metabolite patterns provided information on the location and severity of toxic lesions. Those studies detected the presence of glucosuria and aminoaciduria after exposure to known proximal tubule nephrotoxins such as gentamicin, mercuric chloride, and D-serine (7,8,48). Glucosuria and enhanced excretion of amino acids are both strong indicators of proximal tubule damage in general, likely caused by impaired tubular reabsorption in the proximal tubule via sodium-dependent glucose transport.…”

Analysis of time course 1H NMR metabolomics data by multivariate curve resolution

“…(The profiles shown in this figure come from the data obtained from dosed rat #1, which is used here for illustration purposes as the pure spectral matrices for the other rats were similar to these.) Note that in line with the original work [34] we only analyzed the aliphatic region of the spectra. These results are consistent with reported experimental observations of polyuria, which lasted for up to 5 days post dose.…”

“…Although the two studies have been described extensively elsewhere, [5,6,34] the relevance of their design to the application of curve resolution will be put into perspective. The first study, referred to here as the 'nephrotoxicity study', was acquired to investigate the biochemical effects of mercuric chloride in rats.…”

“…The first study, referred to here as the 'nephrotoxicity study', was acquired to investigate the biochemical effects of mercuric chloride in rats. [34] The second study is referred to as the 'embryogenesis study' and consists of two experiments designed to monitor metabolic changes in Japanese medaka (Oryzias latipes) during the course of embryogenesis. [6] The main goal of the latter experiment was to determine the innate metabolic trajectories of embryogenesis in these fish and later to compare these to metabolic trajectories of the same species in the presence of a toxin or some form of environmental stress.…”

A Perceptive of Mass Spectrometry in Clinical Chemistry: Hyphenation for Benefit of Mankind

“…LC/MS is a very important hyphenation technique used for the clinic chemistry. There are large numbers of reports on the analysis for different compounds to understand nephrotoxicity and hepratoxicity [30][31][32][33] by analysis of urine and serum samples. These studies were carried out to understand the mechanism or as biomarkers.…”