[Determination of pseudouridine in serum by high performance liquid chromatography]

Pseudouridine is a modified nucleoside derived from the degradation of transfer ribonucleic acid. The elevation of modified nucleosides in urine has been suggested to be caused by higher turnover rate of t-RNA in tumor tissue than in healthy tissue, rather than by cell death. A method of pseudouridine determination in serum was developed by high-performance liquid chromatography on a Nova-Pak column (Waters) with 0.04 mol/L KH2PO4 (pH 4.0) as mobile phase. The blood samples were collected and 0.6 mL of serum was treated with 0.4 mL 6% HClO4. The precipitate was centrifuged for 10 min at 3000 r/min. Five-hundred microL of the liquor was dried by air-stream at 60 degrees C. The residue was dissolved with 300 microL mobile phase and 10 microL was injected. The average recovery was 93.50 +/- 2.1%. The calibration curve was linear within the concentration range of 0.7-6.8 micromol/L. The serum pseudouridine concentrations for patients with hepatitis, lung cancer, nephritis and uremia were determined and those of patients with lung cancer and uremia were found significantly higher than those of healthy controls (p<0.05). And for patients treated with He-Ne laser no significant change of the pseudouridine hasn't been found (p<0.05).