Binding of prednisolone to alpha 1-acid glycoprotein

J Steroid Biochem. 1983 Feb;18(2):191-4. doi: 10.1016/0022-4731(83)90087-0.

Abstract

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.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Humans
  • Kinetics
  • Orosomucoid / metabolism*
  • Prednisolone / metabolism*
  • Protein Binding
  • Serum Albumin / metabolism
  • Temperature
  • Transcortin / metabolism

Substances

  • Orosomucoid
  • Serum Albumin
  • Transcortin
  • Prednisolone