Evidence for the existence of a family of biologically active angiotensin I-like peptides in the dog central nervous system.

A family of angiotensin I-like peptides has been derived from endogenous precursors present in dog cerebrospinal fluid after incubation with species homologous renin. These peptides are immunologically and pharmacologically similar to [Ile5]angiotensin I, and have molecular weights ranging between 1300 and 2200 daltons. The presence of precursors in the cerebrospinal fluid able to generate various biologically active angiotensin I-like peptides dissimilar to plasma angiotensin I supports the concept of a local angiotensin I-forming system in the brain.