Postnatal Activity of Angiotensin Converting Enzyme in Rat Brain

The specific activity of angiotensin converting enzyme (ACE) was studied in eight brain regions in rats 2--65 days of age. At 65 days of age the activities in various regions relative to the cortex were: neostriatum, 1,200%; hippocampus/amygdala, 430%; hypothalamus, 190%; cerebellum, 140%; and midbrain, thalamus and pons/medulla, 110%. Significant linear increases were found in the neostriatum, hippocampus/amygdala and cortex at 2--65 days of age, in the pons/medulla and thalamus at 2--42 days of age and in the midbrain at 2--21 days of age. The increase with age was greatest in the neostriatum and the data are consistent with the occurrence of ACE in neurons in this area.