Quantitative analysis of serum amino acid spectrum in osteoarthritis rats / 中华地方病学杂志

ABSTRACT

Objective To quantitatively analyze the dynamic changes of amino acid levels in serum of osteoarthritis rats,and to provide clues for further studies on biomarkers and metabolic mechanisms of osteoarthritis.Methods Sixty healthy male Sprague-Dawley (SD) rats were randomly divided into model group and control group according to their body weight by random number table method,the experimental period was 4,8 and 12 weeks,respectively,ten rats in each group.The left knee hind joints of rats in model group were operated by the modified Hulth method.After 5 days,rats of model group were driven to move for 30 minutes a day.Rats of two groups were fed ordinary solid fodder and drank tap water.At the end of the experimental period,the knee joints were collected for pathological observation.The amino acid content in serum was determined by high performance liquid chromatography-quadrupole ion trap tandem mass spectrometer (HPLC/Q-TRAP-MS/MS).The area under the receiver operating characteristic (ROC) curve (AUC) was used to determine the ability of differential amino acids to diagnose disease,AUC ＞ 0.7-0.9 was certain accuracy,＞ 0.9 was high accuracy.Results Under the light microscope,in control group,the articular cartilage surface was smooth and continuous,and the chondrocytes had good overall morphological structure and distinct layers;in model group,the articular cartilage of rats thinned,the surface was roughness and defect,the chondrocytes degenerated,necrosis and disappeared,and the lesions were aggravated with the extension of observation period.Forty kinds of amino acids were detected.Compared with control group,at 4 weeks after surgery,the level of 24 kinds of amino acids in model group decreased and 14 kinds of amino acids were increased,among which the differences in taurine,glutamine,serine,glutamic acid,aspartic acid,γ-aminobutyric acid and hydroxyproline were statistically significant (P ＜ 0.05);at 8 weeks after surgery,24 kinds of amino acids in model group were increased and 16 were decreased,among which the differences in histidine,serine,glutamic acid,homoarginine,lysine,isoleucine and glycine were statistically significant (P ＜ 0.05);at 12 weeks after surgery,36 kinds of amino acids in model group were decreased,among which the differences in 21 kinds of amino acids were statistically significant (P ＜ 0.05),all of their AUC were not less than 0.740,and the AUC of 14 amino acids were not less than 0.800,and the highest was kynurenine (0.980).Conclusions The model of knee osteoarthritis in rats is established successfully.With the increased time,the progress of osteoarthritis lesions increases,and the amino acid metabolism in osteoarthritis rats is out of order.