Alpha 1- and beta-adrenergic receptors in brown adipose tissue of lean (Fa/?) and obese (fa/fa) Zucker rats: effects of cold-acclimation, sucrose feeding and adrenalectomy

• Published in: Biochemical journal Vol. 249; no. 3; pp. 831 - 838
• Main Authors: Raasmaja, A, York, D.A
• Format: Journal Article
• Language: English
• Published: England 01.02.1988
• Subjects: adipose tissue; Adipose Tissue, Brown - drug effects; Adipose Tissue, Brown - metabolism; Adrenalectomy; Adrenergic beta-Antagonists - pharmacology; Animals; Binding Sites; body weight; Cell Membrane - metabolism; Cold Temperature; cold tolerance; diet study techniques; Female; Male; obesity; Obesity - metabolism; Prazosin - metabolism; Propanolamines - pharmacology; Rats; Rats, Zucker; receptors; Receptors, Adrenergic, alpha - metabolism; Receptors, Adrenergic, beta - metabolism; sucrose; Sucrose - pharmacology
• ISSN: 0264-6021; 1470-8728
• DOI: 10.1042/bj2490831

1. The populations of alpha 1- and beta-adrenergic receptors in brown adipose tissue (BAT) of genetically obese Zucker rats (fa/fa) were studied with [3H]prazosin and [3H]CGP-12177 respectively. 2. The density of alpha 1-adrenergic receptors in BAT was significantly lower in obese than in lean Zucker rats, both at 2-4 months of age and at 6 weeks of age. The density of beta-adrenergic receptors was identical in BAT of lean and obese 6-week-old Zucker rats. 3. Cold-acclimation increased the alpha 1-receptor density significantly in BAT of both lean and obese Zucker rats, and the number of beta-receptors was also somewhat increased. 4. Sucrose feeding did not affect the density of alpha 1-receptors in BAT of lean or obese Zucker rats, but it increased beta-receptor density. 5. Adrenalectomy restored the density of alpha 1-adrenergic receptors in BAT of obese Zucker rats to the value observed in lean rats. 6. It is concluded that there is a direct correlation between alpha 1-receptor density and tissue recruitment, and that alpha 1-receptor density is thus positively correlated with sympathetic activity. beta-Receptor density is apparently better correlated with feeding conditions.