Bailey D N
Department of Pathology, University of California Medical Center, San Diego 92103-8320, USA.
Am J Clin Pathol. 1995 Aug;104(2):180-6. doi: 10.1093/ajcp/104.2.180.
The binding of cocaine (COC) and cocaethylene (CE) in human serum was studied by equilibrium dialysis. Scatchard analysis suggested a high-affinity binder (Ka, 2.56 x 10(4)L/mol; Bo, 7.38 x 10(-5) mol/L) and a low-affinity binder (Ka, 4.47 x 10(3)L/mol; Bo, 2.77 x 10(-4) mol/L) for COC. Two high-affinity binders (Ka, 5.21 x 10(4) L/mol; Bo, 2.54 x 10(-5) mol/L; and Ka, 4.32 x 10(4) L/mol; Bo, 2.43 x 10(-5) mol/L) were discernible for CE. For both compounds additional, very-low-affinity, high-capacity (nonspecific) binding was also seen. Supplementation of serum with specific proteins suggested that the high-affinity binding was due to alpha-1-acid glycoprotein, whereas the low-affinity binding was due to albumin, inasmuch as such supplementation increased the ratio of bound to free drug for both COC and CE.
采用平衡透析法研究了可卡因（COC）和可口卡因（CE）与人血清的结合情况。Scatchard分析表明，COC存在一种高亲和力结合剂（Ka，2.56×10⁴L/mol；Bo，7.38×10⁻⁵mol/L）和一种低亲和力结合剂（Ka，4.47×10³L/mol；Bo，2.77×10⁻⁴mol/L）。对于CE，可识别出两种高亲和力结合剂（Ka，5.21×10⁴L/mol；Bo，2.54×10⁻⁵mol/L；以及Ka，4.32×10⁴L/mol；Bo，2.43×10⁻⁵mol/L）。对于这两种化合物，还观察到了额外的极低亲和力、高容量（非特异性）结合。向血清中添加特定蛋白质表明，高亲和力结合是由于α-1-酸性糖蛋白，而低亲和力结合是由于白蛋白，因为这种添加增加了COC和CE的结合型与游离型药物的比例。
