SPECIFIC, NON-ANGIOTENSIN, [I-125] CGP-42112 BINDING-SITES IN RAT SPLEEN MACROPHAGES

We report the novel expression of a high affinity non-angiotensin II b inding site to [I-125]CGP 42112, predominantly localized to the red pu lp of the rat spleen and to isolated rat spleen macrophages. Binding i s not inhibited by angiotensin II, related peptides or AT(1) or AT(2) receptor ligands, and is not affected by several growth factors and cy tokines involved in macrophage function. Thus, CGP 42112 recognizes bi nding sites other than angiotensin II AT(2) sites in rat macrophages. CGP 42112 and related peptides might influence the regulation of macro phage function. (C) 1994 Academic Press, Inc.