Angiotensin II receptors in adrenal gland, pituitary gland and brain of sino-aortic denervated rats.

Angiotensin II (ANG II) binding sites were quantified in individual adrenal and pituitary glands and brain nuclei of sino-aortic denervated (neurogenically hypertensive) and sham-operated rats by incubation of 16-microns tissue sections with 125I-[Sar1] Ang II, autoradiography, computerized microdensitometry and comparison with 125I-standards. In the anterior pituitary, the number of ANG II binding sites (Bmax) was increased in sino-aortic denervated rats, 764 +/- 39 versus 2025 +/- 340 fmol/mg protein in sham-operated versus sino-aortic denervated. In the adrenal medulla the Bmax was decreased in sino-aortic denervated rats, 3313 +/- 71 versus 2736 +/- 181 fmol/mg protein in sham-operated versus sino-aortic denervated. There were no significant changes in adrenal zona glomerulosa ANG II binding capacity. In the nucleus of the solitary tract the Bmax was decreased, from 1422 +/- 22 fmol/mg protein in sham-operated to 370 +/- 52 fmol/mg protein in sino-aortic denervated rats. These results indicate that changes in ANG II binding occur in peripheral tissues and brain of neurogenic hypertensive rats. Our findings suggest that both peripheral and central ANG II may be associated with the pathophysiology of neurogenic hypertension.