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Objective: To explore the intergrating of N-isopropyl oxamate and serum protein and establish a high performance liquid chromatography (HPLC) detection method of N-isopropyl oxamate (specific inhibitor of testis-specific lactate dehydrogenase (LDH-C4)) in the blood of plateau pikas., Methods: Twenty highland pika 150-200 g, were randomly divided into two groups (n = 10): control group and inhibitor group. Different concentrations of N-isopropyl oxamate were added to examine the intergrating of N-isopropyl oxamate and serum protein. In order to determine its concentration in the pika blood accurately, we used the method of adding trypsin to incubate the serum first, followed by trichloroacetic acid treatment and detecting by HPLC. Results: When the concentrations of N-isopropyl oxamate in the pika serum were added to 0.05 mmol/L, 0.1 mmol/L, 1 mmol/L, 10 mmol/L, 16.7 mmol/L, 33.3 mmol/L and 100 mmol/L, the intergrating rates between N-isopropyl oxamate and plateau pika serum were 100%, 100%, 100%, 86.84%, 54.11%, 40.10% and 20.18%, respectively. The method established in this paper was good on recovery rates, precision and stability. A good linearity was obtained in the range of 0.0125-0.25 mmol/L. When the concentrations of N-isopropyl oxamate in the serum were added to 0. 15 mmol/L,0.3 mmol/L and 1 mmol/L, the recovery rates were 98.05%, 98.98% and 98.12%, respectively; the precision relative standard deviation( RSD) of concentrations were 1.17%, 0.92% and 0.83%, respectively; the stability relative standard deviation (RSD) of concentrations were 1.38%, 1.40% and 0.88%, respectively. The repeatability RSD of the method was 1.76%. Quantitative limit was 0.0125 mmol/L., Conclusion: N-isopropyl oxamate has a strong affinity with plateau pika serum protein that can't be accurately determined with common HIPLC method. It can be accurately determined in the blood by adding trypsinto digest the serum protein first, followed by adding trichloroacetic acid to precipitate the protein.

Aim: To explore the adapting metabolic mechanisms of the plateau zokors to the hypoxic-hypercapnic environment., Methods: The activities of lactate dehydrogenase in serum and tissues, and the content of lactate in serum of plateau zokors in spring, summer and autumn were determined by using method of enzyme analysis. The spectrums of lactate dehydrogenase isoenzymes in serum and tissues of plateau zokors in spring, summer and autumn were analyzed by using method of the discontinuous systemic poly-acrylamide perpendicular plank gel electrophoresis., Results: The activities of lactate dehydrogenase in serum had obvious seasonally difference that were higher in spring and lower in autumn, and the content of lactate in serum showed same changing pattern. The spectrums of lactate dehydrogenase isoenzymes in serum showed five bands that were LDH1, LDH2, LDH3, LDH4 and LDH5 from positive pole to negative pole respectively, it showed clearly two bands in serum of summer that were LDH4 and LDH5 and one band in serum of autumn that was LDH5. The activities of LDH in tissues of skeleton muscle, cardiac muscle and brain were higher compared with the other tissues, it decreased markedly from spring to summer to autumn. In tissues of liver, kidney and lungs, activities of LDH were lower. Activities of LDH in livers, were significantly higher in spring compared that in summer and autumn, which had no obvious difference between summer and autumn. Activities of LDH in kidneys and lungs, showed no obviously difference between spring and summer, which decreased markedly in autumn. The spectrums of lactate dehydrogenase isoenzymes in tissues of cardiac muscle, liver, lungs, kidney, brain and skeleton muscle showed five bands, the spectrums were obvious different in different tissues, and the content of LDH isoenzymes showed seasonal changes in different tissues., Conclusion: Glycolysis levels in plateau zokors had obvious seasonally change which increased in spring and decreased in autumn significantly. It related to the activity of plateau zokors in different seasons and seasonal fluctuation of oxygen and carbon dioxide in burrows of plateau zokors.