The Distribution of Bound Propranolol between the Different HumanSerum Proteins
(1980)
Journal - Molecular Pharmacology
Abstract :
Propranolol binding to the main, isolated, serum proteins wasmeasured by equilibrium
dialysis and compared to its overallbinding in serum measured by the same method. The
results showedthat both saturable and nonsaturable binding phenomena existin serum.
The saturable component involves the binding of propranololto 1-AGP; for this interaction n = 1 and K = 30 450 M-1. Theother component represents multiple nonsaturable
binding toHSA, VLDL, LDL and HDL. The nK values for HSA-propranolol binding
decreasedwhen the HSA concentration used was increased. Warfarin didnot modify
HSA-propranolol binding but palmitic acid decreasedit at high concentrations. Propranolol and erythromycin werefound to probably share the same or a close binding site on
1-AGP.When the measured binding of propranolol to serum was simulatedusing the
parameters obtained from the isolated protein components,the best fit was obtained by
using an HSA concentration of 29µM for the nK value. This discrepancy may be due to
theextrapolation of binding parameters obtained at low HSA concentrationsto the much
higher protein concentrations encountered in serum.Note:
ACKNOWLEDGMENT
We thank Dr. C. Chignell for his help in the English translation of
this manuscript.