title: High-affinity angiotensin receptors in rat adrenal medulla.
abstract: Angiotensin II receptors have been quantitated in single rat adrenal medullas by incubation of tissue sections with 125I-[Sar1]-AII, autoradiography with exposure to 3H-sensitive Ultrofilm, computerized densitometry and comparison with 125I-labelled standards. Rat adrenal medulla contains a single class of high affinity AII receptors with a Ka of 0.84 +/- 0.02 X 10(9) M-1 and a Bmax of 3259 +/- 502 fmol/mg protein, one of the highest densities in AII receptors found in rat tissues. These observations provide evidence for a local site of action of AII in the release of adrenal medullary catecholamines.
mesh_terms: D000313:Adrenal Medulla / Q000378:metabolism*; D000804:Angiotensin II / Q000031:analogs & derivatives / Q000378:metabolism; D000818:Animals; D001345:Autoradiography; D007457:Iodine Radioisotopes; D007700:Kinetics; D051381:Rats; D011945:Receptors, Angiotensin / Q000378:metabolism*; D011956:Receptors, Cell Surface / Q000378:metabolism*
chemical_list: D007457:Iodine Radioisotopes; D011945:Receptors, Angiotensin; D011956:Receptors, Cell Surface; D000804:Angiotensin II; C032651:angiotensin II, Sar(1)-Ile(5)-