The concept of isoreceptors: application to the nicotinic acetylcholine receptor and the gamma-aminobutyric acidA/benzodiazepine receptor complex.

The concept of isoreceptors offers a possible clue to account for pharmacological and biochemical heterogeneity in specific receptor systems. The existence of isozymes has set the foundation for the definition of isoreceptors. The resulting criteria are applied to two central receptor complexes. Accordingly, the nicotinic acetylcholine receptor is defined as an isoreceptor, and research results on the GABA/benzodiazepine receptor are interpreted under the consideration of the possible existence of isoreceptors.