Distribution of Angiotensin‐Converting Enzyme Activity in Specific Areas of the Rat Brain Stem

Abstract

Abstract: Angiotensin‐converting enzyme (ACE) activity was measured by a radiochemical assay in 30 specific areas of the rat brain stem. ACE activity is unevenly distributed, with a 60‐fold difference between the lowest and the highest activity. The area postrema exhibits the highest activity. The substantia nigra (pars reticulata), the locus coeruleus, the areas A 1 and A 2 , the nuclei commissuralis, and tractus solitarii have a substantial ACE activity, whereas the lowest activity is found in the raphe nuclei and the nuclei of the reticular formation.