The binding of chemically different psychotropic drugs to alpha 1-acid glycoprotein

The clinical significance of the high-affinity binding of psychotropic compounds to alpha 1-acid glycoprotein (alpha 1-AGP) in human serum has not been established yet. However, this binding may be of considerable theoretical interest since glycoproteins play a prominent role in the structure of cell membranes. In order to elucidate the nature of the binding to alpha 1-AGP several typical psychotropic compounds (diazepam, haloperidol, imipramine, perazine, phenobarbital and phenytoin) were investigated by means of equilibrium dialysis. The results suggest that among the classical CNS-drugs only those with a tricyclic structure are bound to two binding sites. Possible reason for the widely differing binding of a series of drugs are discussed in terms of their different chemical structure.