[Studies on angiotensin II receptors in the adrenal glands and in the aorta (author's transl)].
The angiotensin II receptor in the rabbit, rat and human adrenal gland and that in the rabbit and rat aorta were studied by using [3H]-angiotensin II ([3H]-AII). The adrenal glands and the aorta of each species were centrifuged at 20,000Xg for 30 min, and pellets which contained 95% of binding sites were collected and diluted by a buffer [20 mM Tris-HCl buffer (pH 7.4), 120 mM NaCl, 0.2% BSA, 1 mM EDTA] and used as a membrane fraction. The binding study was done by incubating the membrane fraction and [3H]-AII. After incubation at 25 degrees C for 30 min, the binding of the membrane fraction and [3H]-AII reached the equilibrium state, and free and bound angiotensin II were separated by 0.48 micrometer filters. Protein concentration was determined according to the method of Lowry. The binding sites fulfilled the criteria of the receptor which has organ and structure specificities, high affinity and reversibility. We could thus measure angiotensin II receptor in this study correctly and concisely. The properties of the angiotensin II receptor were analysed by Scatchard plot. The number of rabbit adrenal receptors (12833 +/- 2115 x 10(-15) mol/mg.protein) (M ++/- SD) was greater than that of the rat (1780 +/- 166 x 10(-15) mol/mg.protein) and that of the human (356 +/- 124 x 10(-15) mol/mg.protein). But the dissociation constant of all species was the same. The number of aorta binding sites was less than that of the adrenal in rabbits and rats. But the dissociation constant of rabbits and rats aorta binding sites was quite similar to that of adrenal glands.
D000311:Adrenal Glands / Q000032:analysis*; D000804:Angiotensin II / Q000378:metabolism*; D000818:Animals; D001011:Aorta / Q000032:analysis*; D001665:Binding Sites; D006801:Humans; D008297:Male; D011817:Rabbits; D051381:Rats; D011945:Receptors, Angiotensin / Q000032:analysis*; D011956:Receptors, Cell Surface / Q000032:analysis*
D011945:Receptors, Angiotensin; D011956:Receptors, Cell Surface; D000804:Angiotensin II