Identification of alpha 2-adrenergic receptors in human fat cell membranes by [3H]chlonidine binding.
3H-clonidine bound to membrane sites of human fat cells, which have the characteristics of alpha 2-adrenoceptors. Specific binding was rapid, reversible and saturable. [3H]Clonidine binding was of high affinity with a KD of 3.9 nM and with a maximal occupancy of 348 fmol/mg protein. The correlation between alpha-adrenergic agonist or antagonist affinities for the membrane [3H]clonidine binding site with their physiological potencies demonstrates the usefulness of the human fat cell as a model for investigating postsynaptic alpha 2-adrenoceptor properties and regulation.
D015057:1-Naphthylamine / Q000031:analogs & derivatives / Q000378:metabolism; D000273:Adipose Tissue / Q000378:metabolism*; D001667:Binding, Competitive; D002462:Cell Membrane / Q000378:metabolism; D003000:Clonidine / Q000378:metabolism*; D006801:Humans; D007093:Imidazoles / Q000378:metabolism; D066298:In Vitro Techniques; D007700:Kinetics; D011941:Receptors, Adrenergic / Q000378:metabolism*; D011942:Receptors, Adrenergic, alpha / Q000378:metabolism*; D015016:Yohimbine / Q000378:metabolism
D007093:Imidazoles; D011941:Receptors, Adrenergic; D011942:Receptors, Adrenergic, alpha; D015016:Yohimbine; D015057:1-Naphthylamine; D003000:Clonidine; C005370:tramazoline