Repeated stress increases the density of angiotensin II binding sites in rat paraventricular nucleus and subfornical organ.

We have studied the properties of angiotensin II binding sites in the paraventricular nucleus, subfornical organ and anterior pituitary lobe of rats subjected to repeated immobilization stress. This treatment produced significant increase in the density of angiotensin II binding sites in these two nuclei without any significant alteration in binding affinity. Repeated stress did not alter angiotensin II binding properties in the anterior pituitary lobe. Our results suggest that brain angiotensin binding sites may have a role in regulation of the stress response.