Glucocorticoid receptors in leukocytes and gill of juvenile coho salmon (Oncorhynchus kisutch).
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.
Maule
A G
AG
Oregon Cooperative Fishery Research Unit, Oregon State University, Corvallis 97331.
Schreck
C B
CB
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*
D011965:Receptors, Glucocorticoid