Alpha 2-adrenergic receptors in brown adipose tissue of infant rats--I. Identification and characteristics of binding sites in isolated plasma membranes.
1. Alpha 2-Adrenoceptor antagonists [3H]yohimbine and [3H]RX 781094 and the partial alpha 2-agonist [3H]clonidine exhibited specific binding to plasma membrane fragments isolated from interscapular brown fat of 7-day-old rats. 2. Competition studies with epinephrine, yohimbine and practolol revealed that [3H]norepinephrine, the principal in vivo agonist acting upon brown adipocytes, can readily bind to alpha 2-adrenoceptors in brown fat of infant rats. 3. The presence of alpha 2-adrenoceptor subclass in brown fat of infant rats may play a role in the sympathetic regulation of this rapidly proliferating tissue.
D002001:Adipose Tissue, Brown / Q000378:metabolism*; D000317:Adrenergic alpha-Antagonists / Q000378:metabolism*; D000818:Animals; D001667:Binding, Competitive; D002462:Cell Membrane / Q000378:metabolism; D003000:Clonidine / Q000378:metabolism; D004082:Dihydroalprenolol / Q000378:metabolism; D004146:Dioxanes / Q000378:metabolism; D019329:Idazoxan; D007700:Kinetics; D009638:Norepinephrine / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains; D011942:Receptors, Adrenergic, alpha / Q000378:metabolism*; D015016:Yohimbine / Q000378:metabolism
D000317:Adrenergic alpha-Antagonists; D004146:Dioxanes; D011942:Receptors, Adrenergic, alpha; D015016:Yohimbine; D004082:Dihydroalprenolol; D003000:Clonidine; D009638:Norepinephrine; D019329:Idazoxan