[3H]2-(2-Benzofuranyl)-2-imidazoline, a highly selective radioligand for I2-imidazoline receptor binding sites

Abstract

2-(2-Benzofuranyl)-2-imidazoline (2-BFI) has recently been characterised as a selective ligand for the I2- of imidazoline-receptor binding site(s) (I2-RBS). The present studies determined the relative levels of specific [3H]2-BFI binding to membrane homogenates of brain and kidney from rat, guinea pig and rabbit and identified the pharmacological characteristics of [3H]2-BFI binding sites in rabbit kidney membranes. Rabbit kidney membranes had the highest relative density of specific [3H]2-BFI binding of all tissues studied (2000 fmol/mg protein). Rabbit brain and guinea pig kidney had moderate levels of specific [3H]2-BFI binding (350-500 fmol/mg protein), while rat kidney and guinea pig an..