Binding of prednisolone to alpha 1-acid glycoprotein.
The binding of prednisolone to alpha 1-acid glycoprotein (AGP) was determined in vitro by equilibrium dialysis. The effects of temperature, protein concentration, and drug concentration were evaluated. The binding ratio (bound/free) correlated well with protein concentration (r = 0.958) and percent bound ranged from 2 to 12% over high to low prednisolone concentrations at physiologic AGP concentrations (100 mg/dl). Temperature changes did not perturb binding. The non-linear regression estimate of the binding constant (nk) was 4.4 x 10(3) M-1 indicative of both low affinity and low capacity of AGP for prednisolone. Overall, contribution of AGP to the total plasma binding of prednisolone is less than 3% when considered in the competitive protein binding system with transcortin and albumin. Disease induced alterations of AGP concentrations are relatively unimportant regarding plasma protein binding of prednisolone.
D006801:Humans; D007700:Kinetics; D009961:Orosomucoid / Q000378:metabolism*; D011239:Prednisolone / Q000378:metabolism*; D011485:Protein Binding; D012709:Serum Albumin / Q000378:metabolism; D013696:Temperature; D014156:Transcortin / Q000378:metabolism
D009961:Orosomucoid; D012709:Serum Albumin; D014156:Transcortin; D011239:Prednisolone