[Binding of (125I)-tyrosyl-bradykinin to subcellular vascular fractions]

The binding of the biologically active bradikinin analog--[125I]-tyr-B to partially purified fractions of plasma membranes from rat and rabbit aorta and from human umbilical veins and arteries has been studied. It was shown that some regions of vascular plasma membranes have a high affinity for the analog (Kac = 2--6.10(8) M-1). The capacity for competitive substitution of angiotensin II and [125I]-angiotensin II-tyr-B for [125I]-tyr-B suggests the similarity of the binding sites of plasma membranes of the two biologically active peptides--bradikinin and angiotensin II.