Douglas J G, Brown G, White C
Hypertension. 1982 Sep-Oct;4(5 Pt 2):III79-84. doi: 10.1161/01.hyp.4.5_pt_2.iii79.
A number of biological responses to angiotensin II have been demonstrated to be modulated acutely by cations, but the exact mechanism has not been elucidated. We have utilized a radioreceptor assay for angiotensin II to determine whether this acute regulatory mechanism could be related to a change in either number or affinity of angiotensin II binding to receptors. Three target tissues were used (adrenal glomerulosa, glomeruli, and uterine smooth muscle). Both mono- and divalent cations influence the kinetics of angiotensin II binding in a similar manner in all tissues. Divalent cations increase the number of receptor sites to a greater extent than did monovalent cations, while monovalent cations changed binding affinity to a greater extent than did divalent cations. These studies demonstrate that both the number and affinity to a greater extent than did monovalent cations, while monovalent cations changed binding affinity to a greater extent than did divalent cations. These studies demonstrate that both the number and affinity of angiotensin receptors can be rapidly modulated by a variety of cations.
