Objective

2

To evaluate the success of Qi-deficiency model of Balb/C-nu mice established by swimming exhaustion test from the view of biomarkers and metabolic pathways by metabonomics.

Method

2

Balb/C-nu mice were randomly divided into the normal group and Qi-deficiency group， Qi-deficiency model was established by swimming with 5% body weight metal fixed at the tail for 15 consecutive days until exhaustion （nose tip immersion time

>

5 s）. The urine metabonomics was analyzed by ultra-high performance liquid chromatography-quadrupole-time-of-flight mass spectrometry （UPLC-Q-TOF/MS）， and the mobile phase was acetonitrile （A）-0.1% formic acid aqueous solution （B） for gradient elution （0-1 min， 5%-8%A； 1-4 min， 8%-8.5%A； 4-5 min， 8.5%-12%A； 5-10 min， 12%-40%A； 10-12 min， 40%-100%A； 12-15 min， 100%A）， the flow rate was 0.3 mL·min

-1

， the injection volume was 10 μL， electrospray ionization （ESI） in positive and negative ion modes was used in MS analysis， the MS data were acquired in full-scan mode from

m

/

z

50-1 000. Principal component analysis （PCA）， orthogonal partial least squares-discriminant analysis （OPLS-DA）， human metabolome database （HMDB）， high collision energy ion fragments collected by MS

E

and tandem MS （MS/MS） ion information were used to identify potential biomarkers. Kyoto Encyclopedia of Genes and Genomes （KEGG） database and MetaboAnalyst 5.0 were used to analyze the corresponding metabolic pathways and pathway enrichment of biomarkers.

Result

2

Endogenous substances in urine of mice in normal group and Qi-deficiency group were obviously separated， and there were 24 biomarkers with significant difference. The metabolic pathways involved in these biomarkers were tricarboxylic acid cycle， glycolysis metabolism， amino acid metabolism， fatty acid metabolism， pyrimidine metabolism， steroid hormone biosynthesis and tryptophan metabolism. Among them， the metabolic pathways related to energy were tricarboxylic acid cycle， glycolysis metabolism， amino acid metabolism， fatty acid metabolism， pyrimidine metabolism and steroid hormone biosynthesis.

Conclusion

2

Through the investigation of urine metabonomics， combined with the physical signs， the Qi-deficiency model established by swimming exhaustion test in Balb/C-nu mice is successfully evaluated， and it is also verified that there is a close correlation between Qi-deficiency and energy metabolism.