N-Acetylcysteine (NAC) protects rats administrated with gadolinium-based contrast agents from renal injury, however, the underlying mechanisms remain unclear.A 1H NMR-based metabolomics approach coupled with OPLS-DA (orthogonal projection to latent structure with discriminant analysis) was used to analyze the effect of NAC on urinary metabolic changes for Chronic Renal Failure Rats administrated with Gd-DTPA (Gd-Diethylenetriamine pentaacetic acid).Combined with univariate analysis of integral area, the significantly changed metabolites were selected to screen out the potential metabolic disturbances that induced by Gd-DTPA and NAC.These researches may attribute to study of the protective effect of NAC from renal failure induced by gadolinium-based contrast agents.The disturbance of energy metabolism, urea cycle and kynurenine metabolism were observed from the CRF group.Gd-DTPA caused the reduction of urinary choline, TMAO, o-HPA, p-HPA, hippurate, glycine, nicotinate and taurine accompanied with the elevation of allantoin.Metabonomic recovery in the NAC group was observed, which implied that NAC protects rats with chronic renal failure from Gd-DTPA induced disturbances of gut microbiota metabolism, liver mitochondria metabolism and kynurenine metabolism.The replenishment of glutathione in cells and the recovery of urea cycle that caused by NAC may protect rats from oxidative damage and renal injury.

BACKGROUND:The intracel ular accumulation of reactive oxygen species leads to oxidative stress. Hypoxia is widespread in physiological and pathological condition. Variation of bone proliferation and differentiation when bone tissues cultured or bone cel s induced toxicity by reactive oxygen species under hypoxia have not yet been reported. OBJECTIVE:To observe the biological characteristics of MC3T3-E1 pretreated with different concentrations of hydrogen peroxide (H2O2) in hypoxia, thus understanding the cel mechanism underlying prolonged bone healing in the elderly with osteoporosis and diabetes. METHODS:The MC3T3-E1 cel s pretreated with different concentrations of H2O2 were cultured in different oxygen concentrations. The proliferation of MC3T3-E1 was detected by cel counting kit-8. The cel differentiation was detected through alkaline phosphatase staining and alizarin red staining. Total RNAs were extracted and used for analyzing the mRNA levels of col age type 1, alkaline phosphatase and Cbfa1. RESULTS AND CONCLUSION:When MC3T3-E1 pretreated with 200μmol/L H2O2 for 6 hours, the cel proliferation was increased with time, but lower than that in the control group. The alkaline phosphatase activity was weakened, and the number of mineralized nodes was decreased at the early stage of differentiation. When MC3T3-E1 pretreated with 400μmol/L H2O2 for 6 hours, the cel proliferation was decreased obviously. The alkaline phosphatase activity was stil weakened, and the number of mineralized nodes was decreased further, but not affected by hypoxia. When MC3T3-E1 pretreated with 400μmol/L H2O2 for 6 hours and then cultured in hypoxia, the mRNA expression of Cbfa1 was decreased, but the mRNA expressions of col age type 1 and alkaline phosphatase were significantly increased. These results suggest that MC3T3-E1 pretreated with low concentration of H2O2 show a significant decrease in proliferation, while MC3T3-E1 pretreated with a high concentration of H2O2 and cultured in hypoxia show a decrease in osteogenic differentiation, especial y at the early stage of alkaline phosphatase formation.

Wistar rats were intragastrically administered with different doses (2, 5 and 10 g / kg body weight) of haematitum. 1H NMR-based metabonomic analysis coupled with multivariate statistical analysis (principal component analysis and partial least squares-discriminant analysis) was used to analyze the metabolic profiles of the urine samples collected from the treated rats. Univariate analysis on the 1H NMR spectra of urine (1 d before administration, 1-5 d post administration) was used to screen out the potential features of haematitum. Significant treatment related changes were observed for the levels of citrate, tuarine, creatinine,α-ketoglutarate, succinate and dimethylglycine, which could be used as potential features of haematitum. A trend of recovery in connection with dose levels was observed overtime. Such biochemical changes indicated that haematitum treatment at the dose of 2, 5 and 10 g / kg body weight affected the Krebs cycle and glucose metabolism, energy metabolism, choline metabolism and dimethylglycine metabolism in rats. These changes may attribute to the disturbances of hepatic function in 10 g / kg body weight group.