Fig. 5.

Angiotensin converting enzyme (ACE) activity in the hypothalamus and pons/medulla of 8- to 10-wk-old mice. For hypothalamus (Hypothal, n = 3–4) and pons/medulla (Pons/Med, n = 5–6), ACE activity was measured in 40 μg of total protein from crude homogenate preparations. Proteolytic activity was measured by monitoring the fluorescence emission (360 nm emission, 480 nm excitation) of o-phthaldialdehyde coupled to histidine-leucine produced from the cleavage of hippuryl-histidine-leucine. ACE activity was determined specifically as captopril-inhibitable proteolytic activity. Values are means ± SE.