Design, synthesis, and in vitro pharmacology of new radiolabeled gamma-hydroxybutyric acid analogues including photolabile analogues with irreversible binding to the high-affinity gamma-hydroxybutyric acid binding sites.

Gamma-hydroxybutyric acid (GHB) is a psychotropic compound endogenous to the brain. Despite its potential physiological significance, the complete molecular mechanisms of action remain unexplained. To facilitate the isolation and identification of the high-affinity GHB binding site, we herein report the design and synthesis of the first (125)I-labeled radioligands in the field, one of which contains a photoaffinity label which enables it to bind irreversibly to the high-affinity GHB binding sites.