Steroid Hormones as Feedback Regulators of Brain Angiotensinogen and Catecholamines

¹ Department of Medicine, University of California, San Diego, La Jolla, Calif.

Perturbation of peripheral volume homeostasis results in regionally selective changes in brain angiotensinogen, the putative precursor of angiotensin II. The results presented indicate that brain angiotensinogen may be affected in a selective and regional manner and that steroid hormones may mediate these changes. Sex and adrenal steroids appear to affect angiotensinogen levels in different areas of the rat brain. Brain angiotensinogen and norepinephrine levels are linearly and positively correlated. Reserpinization leads to selective increases in brain angiotensinogen which are shown to be attributable to adrenal corticosterone secretion. These results point to steroids as messengers controlling in part the level of activity of brain catecholaminergic and peptidergic systems which regulate the peripheral cardiovascular system.