Specific labelling of postsynaptic ?1 adrenoceptors in rat heart ventricle by 3H-WB 4101

Abstract

The α-adrenoceptor ligand, ³H-WB 4101 binds to a single population of independent sites in the rat heart ventricle. These sites are not affected by chemical sympathectomy with 6-hydroxydopamine and thus appear to be located postsynaptically. The relative order of potencies for displacement of ³H-WB 4101 binding: prazosin>phentolamine>yohimbine, is characteristic of that of the α₁ type of adrenoceptors. In heart ventricle ³H WB-4101 thus seems to label specifically postsynaptically located α₁-adrenoceptors. The significance of the specificity of this ligand is discussed with relevance to its use in the central nervous system.