SHEEP HYPOTHALAMUS CONTAINS A NON‐ANGIOTENSIN LIGAND FOR TYPE 1 AND TYPE 2 ANGIOTENSIN II RECEPTORS

Abstract

1. The aim of this study was to determine whether the brain contains an alternative ligand for angiotensin II (AII) receptors. 2. A radioreceptor assay based upon bovine cerebellar membranes (Type 2 AII receptors) was used to monitor the partial purification of an AII‐like material from sheep hypothalami. 3. This material displaces 125I‐[Sar1, Ala8I‐AII from both type 1 (rat adrenal capsuIar membranes) and Type 2 AII receptors in a manner parallel to that of AIL It has a size of ∼30000 Da, is strongly cationic, is stable to boiling but is destroyed by trypsin. It is not recognized by AII antisera. 4. These data provide direct evidence for a non‐angiotensin endogenous ligand for brain AII rec..