Treatment of mouse brain cytosol with dextran-coated charcoal and high salt does not reveal a new glucocorticoid binder.
Incubation of steroid-free whole mouse brain cytosol from adrenalectomized-ovariectomized mice with saturating concentrations of tritiated dexamethasone was found to label all Type I as well as all Type II adrenocorticosteroid receptors. The quantitative and brain regional distribution of residual dexamethasone binding in cytosols pre-treated with dextran-coated charcoal (DCC) and 300 mM KCl was indistinguishable from that for tritiated aldosterone-Type I receptor complexes under the same conditions. We therefore conclude that the dexamethasone binding sites remaining after DCC and KCl treatment of steroid-free brain cytosol are due to the presence of Type I receptors. The differential sensitivity of Type I and Type II receptors to the DCC/KCl treatment paradigm may be useful in the purification of Type I receptors.
Luttge
W G
WG
Department of Neuroscience, University of Florida College of Medicine, Gainesville 32610.
Kang
C G
CG
Rupp
M E
ME
Emadian
S M
SM
D000315:Adrenalectomy; D000450:Aldosterone / Q000378:metabolism; D000732:Androstanols / Q000378:metabolism; D000818:Animals; D001921:Brain / Q000187:drug effects / Q000378:metabolism*; D002606:Charcoal / Q000494:pharmacology*; D003600:Cytosol / Q000187:drug effects / Q000378:metabolism; D003907:Dexamethasone / Q000378:metabolism; D003911:Dextrans / Q000494:pharmacology*; D005260:Female; D051379:Mice; D010052:Ovariectomy; D011189:Potassium Chloride / Q000494:pharmacology*; D011965:Receptors, Glucocorticoid / Q000378:metabolism*
D000732:Androstanols; D003911:Dextrans; D011965:Receptors, Glucocorticoid; D002606:Charcoal; D000450:Aldosterone; D011189:Potassium Chloride; C038341:RU 26988; C049154:11,17-dihydroxy-6-methyl-17-(1-propynyl)androsta-1,4,6-triene-3-one; D003907:Dexamethasone