Abstract: ¹H NMR spectroscopy has been used to assess chronic toxicological effects of rare earth. Male Wistar rats have been administrated orally with La(NO₃)₃ at doses of 0.2,2.0,10 20mg/kg body weight for six months. The analysis for ¹H NMR spectra of rats serum and rats urine after dosing rare earth was reported. The ¹H NMR variation of numerous low-Mr metabolites, including ketone bodies, lactate, glucose, urea, citrate and various amino acids, provided a sensitive measure of La³⁺-induced renal and liver damage and information on abnormal patterns of metablite excretion. The assay of some biochemical indexes in plasma supported NMR results. ¹H NMR techniques could be applied to clinical diagnosis of abnormal metabolism of the inborn disease and the investigation of the toxicological effects of other drugs.

Key words: Rare earth, Biofluids, NMR, Metabolism