Brain angiotensin-converting enzyme activity in experimental hypertensive rats.

Angiotensin-converting enzyme (ACE) activity was measured in six areas of the brain of normotensive and experimental hypertensive rats; one-clip, one-kidney (1-c, 1-k) and one-clip, two-kidney (1-c, 2-k) Goldblatt hypertensive (GH) rats. ACE activity was consistently high in the thalamus of normotensive and both 1-c, 1-k and 1-c, 2-k GH rats. However, the enzyme activity in the hypothalamus of 1-c, 2-k GH rats was significantly higher than that of normotensive rats, while there was no significant difference in the enzyme activity between normotensive and 1-c, 1-k GH rats. These results demonstrate that in 1-c, 2-k GH rats, increased ACE activity in the brain may play a central role in the hypertension.