Trnavská Z, Trnavský K, Zlnay D
Eur J Clin Pharmacol. 1984;26(4):457-61. doi: 10.1007/BF00542141.
The protein binding of piroxicam in synovial fluid and plasma from patients with rheumatoid arthritis was studied in vitro by equilibrium dialysis. The binding parameters were calculated from the experimental data with the Scatchard model, assuming binding to two classes of sites. Each plasma sample was diluted to an albumin concentration equal to that of synovial fluid from the same patient. The association constants for primary and secondary binding sites in the concentration range of piroxicam 4.5-90 X 10(-5) mol/l were similar in synovial fluid and in plasma. For synovial fluid K1 = 2.38 X 10(5) l/mol and K2 = 2.29 X 10(3) l/mol; for plasma K1 = 1.93 X 10(5) l/mol and K2 = 2.08 X 10(3) l/mol. The number of binding sites was also the same in the two fluids. Although the concentration of piroxicam in synovial fluid was about half that in plasma, the binding of piroxicam to protein in synovial fluid was the same as in plasma.
采用平衡透析法在体外研究了类风湿性关节炎患者滑液和血浆中吡罗昔康的蛋白结合情况。利用Scatchard模型，假定其与两类位点结合，从实验数据计算结合参数。将每个血浆样本稀释至与同一患者滑液中白蛋白浓度相同。在吡罗昔康浓度范围为4.5 - 90×10⁻⁵mol/L时，滑液和血浆中一级和二级结合位点的缔合常数相似。滑液中，K1 = 2.38×10⁵l/mol，K2 = 2.29×10³l/mol；血浆中，K1 = 1.93×10⁵l/mol，K2 = 2.08×10³l/mol。两种液体中的结合位点数也相同。尽管滑液中吡罗昔康的浓度约为血浆中的一半，但吡罗昔康与滑液中蛋白质的结合与血浆中的相同。
