Specific, non-angiotensin, [125I]CGP 42112 binding sites in rat spleen macrophages

We report the novel expression of a high affinity non-angiotensin II binding site to [125I]CGP 42112, predominantly localized to the red pulp of the rat spleen and to isolated rat spleen macrophages. Binding is not inhibited by angiotensin II, related peptides or AT1 or AT2 receptor ligands, and is not affected by several growth factors and cytokines involved in macrophage function. Thus, CGP 42112 recognizes binding sites other than angiotensin II AT2 sites in rat macrophages. CGP 42112 and related peptides might influence the regulation of macrophage function.