AJP - Endocrinology and Metabolism, Vol 238, Issue 6 552-E563, Copyright © 1980 by American Physiological Society

ARTICLES

Stereospecific stimulation of brown adipocyte respiration by catecholamines via beta 1-adrenoreceptors

L. Bukowiecki, N. Follea, A. Paradis and A. Collet

Regulation of respiration by catecholamines was studied in adipocytes isolated from interscapular brown adipose tissue of warm-acclimated rats by rapid digestion of collagenase. (-)-Norepinephrine stimulated adipocyte respiration 10-12 times above basal values in less than 3 min. (Vmax = 410 +/- 29.5 nmol O2 . min-1 . 10(-6) cells-1). Stimulated respiration remained stable for at least 20 min, provided that cells were incubated in balanced salt media containing bicarbonate. The maximal capacity of total brown adipose tissue for norepinephrine-stimulated respitarion was estimated at 1.5 ml O2/min per rat. beta-Adrenergic agonists increased calorigenesis stereospecifically with an order of potency expected for respiratory stimulation via adrenoceptors of the beta 1-subtype: (-)-isoproterenol (1/2 Vmax = 2 nM) greater than (-)-norepinephrine (1/2 Vmax = 20 nM) approximately equal to (-)-epinephrine (1/2 Vmax = 40 nM) greater than corresponding (+)-stereoisomers. The alpha-adrenergic agonist phenylephrine (1/2 Vmax = 5 microM) stimulated adipocyte respiration as rapidly and as effectively as beta-agonists. Although alpha-adrenoreceptors are present in brown adipose tissue, studies with alpha- and beta-adrenergic antagonists revealed that norepinephrine elicits thermogenesis at physiological concentrations (less than or equal to 1 microM) predominantely via beta 1-adrenergic pathways.

This article has been cited by other articles:

				W. T. L. Festuccia, R. Guerra-Sa, N. H. Kawashita, M. A. R. Garofalo, E. A. Evangelista, V. Rodrigues, I. C. Kettelhut, and R. H. Migliorini Expression of glycerokinase in brown adipose tissue is stimulated by the sympathetic nervous system Am J Physiol Regulatory Integrative Comp Physiol, June 1, 2003; 284(6): R1536 - R1541. [Abstract] [Full Text] [PDF]

				J. Zhao, B. Cannon, and J. Nedergaard alpha 1-Adrenergic Stimulation Potentiates the Thermogenic Action of beta 3-Adrenoreceptor-generated cAMP in Brown Fat Cells J. Biol. Chem., December 26, 1997; 272(52): 32847 - 32856. [Abstract] [Full Text] [PDF]

				C. Atgie, F. D'Allaire, and L. J. Bukowiecki Role of beta 1- and beta 3-adrenoceptors in the regulation of lipolysis and thermogenesis in rat brown adipocytes Am J Physiol Cell Physiol, October 1, 1997; 273(4): C1136 - C1142. [Abstract] [Full Text] [PDF]

				A. Matthias, K. B. E. Ohlson, J. M. Fredriksson, A. Jacobsson, J. Nedergaard, and B. Cannon Thermogenic Responses in Brown Fat Cells Are Fully UCP1-dependent. UCP2 OR UCP3 DO NOT SUBSTITUTE FOR UCP1 IN ADRENERGICALLY OR FATTY ACID-INDUCED THERMOGENESIS J. Biol. Chem., August 11, 2000; 275(33): 25073 - 25081. [Abstract] [Full Text] [PDF]