ABSTRACT
Objective: To establish an accurate and selective UPLC-MS/MS) method for the determination of afatinib in rat plas-ma. Methods: Protein precipitating by acetonitrile was used to prepare the samples. A CORTECS BEH C18column ( 50 mm × 2. 1 mm, 1. 6 μm) was used to separate the analytes at 40℃. The mobile phase consisted of acetonitrile and water (0. 1% formic acid) with the flow rate of 0. 4 ml·min-1. The analytes were quantified by multiple reaction monitoring ( MRM) mode with positive electrospray ionization, while the target fragment ions were m/z 486. 19→112. 1 for afatinib and m/z 557. 3→112. 15 for neratinib (IS). Results: The calibration curve obtained good linearity for afatinib within the range of 1–200 ng·ml-1(r=0. 998 1), and the LLOQ in rat plasma was 1. 0 ng/ml. The intra-and inter-day precisions were both≤9. 51% . The recovery of afatinib from plasma was above 77. 1% . After intragastric administration and intravenous administration of afatinib in rats, the t1/2was 7. 19 h and 2. 69 h, Cmax was 97. 78 ng·ml-1and 123. 37 ng·ml-1,and AUC(0-∞)was 1 505. 4 ng·ml-1·h and 405. 55 ng·ml-1·h, respectively. Con-clusion: The validated method can be applied in the pharmacokinetic study of afatinib at the intragastric and intravenous dosage of 10 and 2 mg·kg-1, respectively.
ABSTRACT
To investigate the effect of MMP-26 on human glioma angiogenesis and the possible mechanism.Methods The MMP-26 plasmid and empty plasmid pcDNA3.1 were stably transfected into U251 cells to establish a nude mice xenograft model,and then an in vitro human tumor tissue-based three-dimensional angiagenic model.Tissue disks were visually assessed over time to determine the percentage of wells that developed an angiogenic response(I％) and the density and length of neovessel growth were graded at intervals using a semiquantitative visual growth-rating scheme (angiogenic index,AI,0-16scale) in groups of MMP-26 transfected U251 cells (U251-MMP-26),pcDNA3.1 vector-transfected U251 cells (U251-pcDNA3.1) and non-transfected U251 cells (U251).RT-PCR and immunohistochemistry were used to detect the expression of mRNA and protein of MMP-26 and VEGF in groups of U251-MMP-26,U251-pcDNA3.1 and U251.Immunohistochemical localization of CD31 was determined in the endothelial tubes invading the fibrin-thrombin clot matrix.Results Immunohistochemical endothelial cell markers CD31 was positive in the vascular tubes invading the fibrin-thrombin clot matrix,confirming their endothelial origin.The angiogenesis results showed that difference of length of micro capillaries,density of branches,and the area occupied between U251-MMP-26 groups and control groups were significant.The percentage of tumor implants that developed invasion (I％) and the angiogenic index AI in U251-MMP-26 group on day 14 were higher than those of U251-pcDNA3.1 group and U251 group (P ＜ 0.05).The trends of I％ and AI in 14 days were significant compared with those in control groups.The expression of mRNA and protein of MMP-26and VEGF in U251-MMP-26 group was significantly higher in U251-MMP-26 group than those in U251-pcDNA3.1 group and U251 group(P ＜0.01).Conclusion The effect of MMP-26 on promoting glioma angiogenesis may be related to the increased expression of VEGF,which can be used as targets for anti-tumor therapy.