The biochemical effects of gadolinium chloride were studied using high-resolution IH nuclear magnetic resonance （NMR） spec- troscopy to investigate the biochemical composition of tissue （liver and kidney） aqueous extracts obtained from control and gadolinium chloride （GdCl3） （10 and 50 mg/kg body weight, intraperitoneal injection, i.p.） treated rats. Tissue samples were collected at 48, 96 and 168 h p.d. after exposure to GdCI3, and extracted using methanol/chloroform solvent system. ^1H NMR spectra of tissue extracts were analyzed by pat- tern recognition using principal components analysis. The liver damages caused by GdCl3 were characterized by increased succinate and decreased glycogen level and elevated lactate, alanine and betaine concentration in liver. Furthermore, the increase of creatine and lactate, and decrease of glutamate, alanine, phosphocholine, glycophosphocholine （GPC）, betaine, myo-inositol and trimethylamine N-oxide （TMAO） levels in kidney illustrated kidney disturbance induced by GdCl3.
High resolution magic angle spinning （MAS）-^1H nuclear magnetic resonance （NMR） spectroscopic-based metabonomic approach was applied to the investigation on the acute biochemical effects of Ce（NO3）3. Male Wistar rats were administrated with various doses of Ce（NO3）3（2, 10, and 50 mg·kg^- 1 body weight）, and MAS ^1H NMR spectra of intact liver and kidney tissues were analyzed using principal component analysis to extract toxicity information. The biochemical effects of Ce（NO3）3 were characterized by the increase of triglycerides and lactate and the decrease of glycogen in rat liver tissue, together with an elevation of the triglyceride level and a depletion of glycerophosphocholine and betaine in kidney tissues. The target lesions of Ce（NO3）3 on liver and kidney were found by MAS NMR-based metabonomic method. This study demonstrates that the combination of MAS ^1H NMR and pattern recognition analysis can be an effective method for studies of biochemical effects of rare earths.
Metabolic profiles caused by rare earth complex were investigated using NMR and ICP-MS techniques. Male and female Wistar rats were treated orally with Changle （A kind of rare earth complex applied in agriculture to raise the production of crops） at dose of 2, 5 and 20 mg·kg^-1 body weight/day respectively for 90 d. Urine and serum samples are collected on 90 d. The relative concentrations of important endogenous metabolites in urine and serum are determined from ^1H NMR spectra and the contents of the four rare earth elements （La, Ce, Pr and Nd） constituting Changle in the serum samples are measured by ICP-MS technique. Changle-induced renal and liver damage in rats is found based on the increase in the amounts of the amino acids, trimethylamine N-oxide, N, N-dimethyglycine, dimethylamine, succinate, α- ketoglutarate and ethanol as well as rare earth concentrations. The similarities and differentiations are found in the alteration patterns of metabolites and rare earth concentrations in serum.
