title: Glucocorticoid receptors in leukocytes and gill of juvenile coho salmon (Oncorhynchus kisutch).
abstract: We demonstrated that cytosol from the gill of coho salmon (Oncorhynchus kisutch) had saturable, high affinity, low capacity binding to radiolabeled [3H]cortisol (Kd = 2.24 +/- 0.28 nM, mean +/- 1 SE; Nmax = 41.4 +/- 7.4 fmol/mg protein) and radiolabeled [3H]triamcinolone acetonide (TA; Kd = 0.38 +/- 0.03 nM, Nmax = 37.8 +/- 4.9 fmol/mg protein). Similarly, TA bound to cytosolic fractions of leukocytes harvested from spleen (Kd = 0.32 +/- 0.03 nM, Nmax = 8.3 +/- 2.0 fmol/mg protein) and anterior kidney (Kd = 0.37 +/- 0.03 nM, Nmax = 30.2 +/- 5.2 fmol/mg protein) and to whole leukocytes from spleen (Kd = 0.30 +/- 0.04 nM, Nmax = 445 +/- 57 sites/cell) and anterior kidney (Kd = 0.40 +/- 0.04 nM, Nmax = 1198 +/- 180 sites/cell). The competition hierarchies of steroid competitors were the same for both ligands and all tissues (TA greater than cortisol greater than 17 alpha-hydroxyprogesterone greater than cortisone greater than aldosterone greater than testosterone). The differences in ligand binding in leukocytes from spleen and anterior kidney are consistent with previously reported organ-dependent sensitivity of leukocytes to cortisol.
authors.affiliation: Oregon Cooperative Fishery Research Unit, Oregon State University, Corvallis 97331.
authors.forename: A G
authors.initials: AG
authors.lastname: Maule
authors.forename: C B
authors.initials: CB
authors.lastname: Schreck
mesh_terms: D000818:Animals; D001667:Binding, Competitive / Q000502:physiology; D003600:Cytosol / Q000378:metabolism; D005880:Gills / Q000378:metabolism*; D007962:Leukocytes / Q000378:metabolism*; D011965:Receptors, Glucocorticoid / Q000378:metabolism*; D012474:Salmon / Q000378:metabolism*
chemical_list: D011965:Receptors, Glucocorticoid