Respective degree of expression of beta 1-, beta 2- and beta 3-adrenoceptors in human brown and white adipose tissues.
1. The possible existence of a beta 3-adrenoceptor in human brown and white adipose tissues was investigated by mRNA expression and binding studies. 2. The relative amounts of beta 1-, beta 2- and beta 3-adrenoceptor mRNA, as determined by total RNA Northern blot analysis in newborn brown adipose tissue, were 28, 63 and 9% respectively of the total beta-adrenoceptor mRNA. 3. The beta 1/beta 2-adrenoceptors of human brown adipose tissue plasma membranes were characterized using [3H]-CGP 12177 as a ligand. Their Kd and Bmax values were 1.9 nM and 156 fmol mg-1 of membrane proteins, respectively. The beta 3-adrenoceptor was characterized by use of the new specific radioligand [3H]-SB 206606. The binding of this ligand was stereospecifically displaced by the active R,R- or the inactive S,S-enantiomer of BRL 37344 up to a concentration of about 10 microM. The Kd and Bmax values of the brown adipose tissue membrane beta 3-adrenoceptors were 87 nM and 167 fmol mg-1 of proteins, respectively. A low affinity [3H]-CGP 12177 binding site population was also detected in these membranes. 4. In human omental white adipose tissue, no beta 3-adrenoceptor mRNA could be detected in total RNA Northern blots and the beta 1-and beta 2-adrenoceptor mRNAs represented 9 and 91%, respectively of the total beta-adrenoceptor mRNA, and no specific binding of [3H]-SB 206606 could be measured.
Deng
C
C
Départment de Biochimie Médicale, Centre Médical Universitaire, Genève, Switzerland.
Paoloni-Giacobino
A
A
Kuehne
F
F
Boss
O
O
Revelli
J P
JP
Moinat
M
M
Cawthorne
M A
MA
Muzzin
P
P
Giacobino
J P
JP
D000273:Adipose Tissue / Q000378:metabolism*; D002001:Adipose Tissue, Brown / Q000378:metabolism*; D000318:Adrenergic beta-Agonists / Q000378:metabolism; D000319:Adrenergic beta-Antagonists / Q000378:metabolism; D000328:Adult; D000368:Aged; D001665:Binding Sites; D004983:Ethanolamines / Q000378:metabolism; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011412:Propanolamines / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism*; D011943:Receptors, Adrenergic, beta / Q000235:genetics / Q000378:metabolism*; D018342:Receptors, Adrenergic, beta-1 / Q000235:genetics / Q000378:metabolism; D018343:Receptors, Adrenergic, beta-2 / Q000235:genetics / Q000378:metabolism; D022702:Receptors, Adrenergic, beta-3; D013237:Stereoisomerism
D000318:Adrenergic beta-Agonists; D000319:Adrenergic beta-Antagonists; D004983:Ethanolamines; D011412:Propanolamines; D012333:RNA, Messenger; D011943:Receptors, Adrenergic, beta; D018342:Receptors, Adrenergic, beta-1; D018343:Receptors, Adrenergic, beta-2; D022702:Receptors, Adrenergic, beta-3; C057368:BRL 37344; C033394:CGP 12177