AUTORADIOGRAPHIC EVIDENCE OF ANGIOTENSIN II BINDING SITES IN THE HUMAN ADRENAL GLAND

Angiotensin II binding sites in human adrenal glands obtained at autopsy were investigated. The tissue sections were incubated with 125I-angiotensin II and analyzed using [3H]-Ultrofilm autoradiography with image analysis coupled to computerized microdensitometry. In addition, a comparison was made with 125I-standards. A single type of specific, high affinity binding sites was found in the zona glomerulosa and medulla. The rank order for inhibition of the binding in the zona glomerulosa and medulla was [Sar1, Ile8]-angiotensin II and Des-Asp1-[Ile8]angiotensin II > native angiotensin II = angiotensin III >>> angiotensin I, αhuman atrial natriuretic polypeptide (ANP-(99-126)), substance P and methionineenkephalin. The possibility that angiotensin II plays a significant role in function of the human adrenal zona glomerulosa and medulla by interacting with specific, high affinity receptors, Warrants further attention.