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OBJECTIVE: To establish a rapid and sensitive liquid chromatography-tandem mass spectrometry(LC-MS/MS) method for quantification of vincristine sulfate (VCR) in dog plasma and to study the pharmacokinetics of vincristine sulfate thermosensitive liposomes (VSTL) in dogs. METHODS: The plasma was extracted with terl-butyl methyl ether (TBME). VCR and IS(vinblastine sulfate) were separated on an Agela Venusil XBP C18(2.1 mm × 30 mm, 3.0 μm) with a mobile phase gradient at a flow rate of 0.4 mL · min-1. The injection volume was 10 μL. An Agilent 6460A QQQ triple-quadrople mass spectrometer equipped with an electros-pray ionization(ESI) source was used as detector and was operated in positive ion mode. Multiple-reaction monitoring(MRM) was performed and the m/z of ions selected for quantitation were m/z 825.4→807. 2(VCR) and m/z 811.3→223.9(IS, vinblastine sulfate). Dogs were injected VSTL and vincristine sulfate injection (VSI) via vein at the dose of 0.07 mg-1, respectively. VCR and internal standard were quantified in dog plasma using a high-performance liquid chromatography-tandem mass spectrometry, Pharmacokinetic parameters were calculated, and a comparative study of VSTL and VSI with six dogs was conducted. RESULTS: The chromatograms showed no endogenous interfering peaks in blank dog plasma. The linear range of VCR in plasma was 0.25-500 ng · mL-1 (r=0.994 3). The lower limit of quantification was 0.25 ng · mL-1. The intra-run and inter-run relative standard deviations(RSD) were less than 15%. The pharmacokinetic parameters of VSTL and VSI were as following: ρmax (121.00 ± 42.31) and (61 ±23.36) ng · mL-1; t1/2λz(23.95±9.03) and (37.91±8.02) h; CLz(0.37±0.07) and (0.35 ±0.09) L · h · kg-1; Vz(12.15 ±2.14) and (18.95 ±3.27) L · kg-1; AUC0-t(144.87 ± 1.10) and (127.7 ±2.45) ng · h · mL-1; AUC0-∞ (152.97 ±12.56) ng · h · mL-1; and (131.61 ±13.22) ng · h · mL-1. CONCLUSION: The method is shown to be sensitive, accurate, and convenient for assaying the concentration of vincristine sulfate in preclinical pharmacokinetic studies. The ρmax and AUC of VSTL are significantly higher than VSI after intravenous infusion, the other pharmacokinetic parameters are no significant difference.
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@#ObjectiveTo detect the levels of bone morphogenetic protein-2(BMP-2) mRNA in gunshot fracture healing of the rabbits.MethodsA model of primary treating gunshot fracture of the rabbit with external fixator and the real time fluorescence quantitative reverse transcription polymerase chain reaction(FQ-RT-PCR) technology with SYBR Green I were established.The levels of BMP-2 mRNA 1,2,3 and 4 weeks after operation were detected with FQ-RT-PCR respectively.ResultsIn the control group,BMP-2 mRNA of the bone tissue began to rise at the first week after fracture and the peak of mRNA expression appeared at the second week.The expression returned to normal at the forth week.In the experimental group,the BMP-2 mRNA rose more slowly that it arrived peak stage at the third week and was significantly lower in experimental group than that in control group at the same phases.ConclusionReal time FQ-RT-PCR is a good method for measuring the levels of BMP-2 mRNA during gunshot fracture healing.The mRNA expression rose more slowly and was significantly lower in gunshot fracture than in common fracture at the same phases.