Bolger GT ; Weissman BA ; Lueddens H ; Basile AS ; Mantione CR ; Barrett JE ; Witkin JM ; Paul SM ; Skolnick P ;

Brain Res vol. 338 (2)   pp. 366-70, 15 Jui 1985

Four classes of non-mammalian vertebrates were examined for the presence of both 'brain-specific' and 'peripheral-type' binding sites for benzodiazepines in the central nervous system. 'Brain-specific' binding sites for benzodiazepines were found in the central nervous systems of all non-mammalian vertebrates studied. However, in contrast to mammals, either very low or undetectable levels of 'peripheral-type' binding sites for benzodiazepines were observed in the central nervous systems of these non-mammalian vertebrates. Furthermore, the density of 'peripheral-type' binding sites for benzodiazepines in non-mammalian vertebrate heart was less than or equal to 2% of that found in mammalian cardiac tissue. These findings suggest a very late evolutionary appearance of 'peripheral-type' binding sites for benzodiazepines, implying that these sites may have (a) highly specialized function(s) in both peripheral tissues and the central nervous system.

Animal ;  Benzodiazepinones: metabolism ;  Brain Chemistry ;  Comparative Study ;  Evolution ;  Flunitrazepam: metabolism ;  Lizards ;  Male ;  Organ Specificity ;  Pigeons ;  Radioligand Assay ;  Rana catesbeiana ;  Rats ;  Rats,Inbred Strains ;  Receptors,GABA-A: analysis ;  Trout ;  Vertebrates: metabolism ;  54270 ;