Cation dependence of high-affinity angiotensin II binding to adrenal cortex receptors

The specific binding of monoiodinated angiotensin II by particulate receptors from the bovine adrenal cortex is enhanced by addition of sodium and potassium ions, but not other cations. In the presence of 140 millimolar sodium, increased uptake of angiotensin II by adrenal receptors is associated with the appearance of high-affinity binding sites with an association constant of 2 x 10(9) liters per mole.