Metabonomics analysis of serum from rats given long-term and low-level cadmium by ultra-performance liquid chromatography–mass spectrometry

Abstract

1. This study evaluated the toxicity of chronic exposure to low-level cadmium (Cd) in rats using ultra-performance liquid chromatography–mass spectrometry (UPLC–MS). Forty male Sprague–Dawley rats were randomly assigned to four groups, namely, the control group, low-dose group (0.13 mg/kg·bw), middle-dose group (0.8 mg/kg·bw) and high-dose group (4.89 mg/kg·bw). The rats continuously received CdCl₂ via drinking water for 24 weeks. Serum samples were collected for metabonomics analysis. The data generated from the UPLC–MS was analysed using principal components analysis (PCA) and partial least-squares discriminant analysis (PLS-DA). PLS-DA model with satisfactory explanatory and predictive ability is capable of discriminating the treatment groups from the control group.

2. Finally, the 10 metabolites were identified and showed significant changes in some treatment groups compared with that in the control group (p < 0.0167 or p < 0.003). Exposure to Cd resulted in increased intensities of lysophosphatidic acid (P-16:0e/0:0), glycocholic acid, bicyclo-prostaglandin E2, lithocholyltaurine, sulfolithocholylglycine, lysophosphatidylethanolamine (20:5/0:0) and lysophosphatidylcholine (20:0), as well as decreased intensities of 3-indolepropionic acid, phosphatidylcholine (18:4/18:0) and 15S-hydroxyeicosatrienoic acid in rat serum.

3. Results suggest that exposure to Cd can cause disturbances in the lipid metabolism, amino acid metabolism, nervous system, antioxidant defence system, liver and kidney function.

Keywords:

• Cadmium
• metabonomics
• rat serum
• toxicity
• UPLC–MS

Acknowledgements

Financial support from China National Center for Food Safety Risk Assessment is acknowledged. The laboratory of nutrition and food hygiene in Harbin Medical University is the key laboratory of Heilongjiang Province and Heilongjiang Higher Education Institutions.

Declaration of interest

The authors declared that they have no conflicts of interest in the work.

Supplementary material available online