Journal of Clinical Endocrinology & Metabolism, Vol 81, 368-375, Copyright © 1996 by Endocrine Society

ARTICLES

Evidence for numerous brown adipocytes lacking functional beta 3- adrenoceptors in fat pads from nonhuman primates

N Viguerie-Bascands, A Bousquet-Melou, J Galitzky, D Larrouy, D Ricquier, M Berlan and L Casteilla
CNRS URA 1937, UPS-IFR Louis Bugnard, Toulouse, France.

Brown adipose tissue (BAT) is involved in the control of energy balance and has been demonstrated to be activated through beta 3-adrenoceptor (beta 3-AR) occupation in rodents. The ability to specifically activate energy expenditure via this receptor is of great interest for the treatment of obesity. Nevertheless, the extent of BAT and the presence of a functional beta 3-AR in humans are now debated, and this situation is difficult to clarify for evident practical and ethical reasons. We investigated the occurrence of brown adipocytes in fat deposits of prepubertal baboons using antibodies raised against uncoupling protein (UCP) in Western blotting and immunocytology experiments. UCP was detected in all types of fat pads studied and was revealed in multilocular cells. Pericardiac and axillary adipose tissues displayed large amounts of UCP and can be assimilated to typical BAT. Most of the other pads looked like white adipose tissue, but exhibited areas with clusters of brown adipocytes and, thus, can be assimilated to the convertible adipose tissue as previously described in rodents. The presence of beta 3-ARs was evaluated by both beta 2-agonist-stimulated lipolysis and messenger ribonucleic acid (mRNA) expression studies. There was no significant lipolytic effect of any of the beta 3-AR agonists tested (SR 58611A, BRL 37344, CGP 12177, or CL 316243) in either white or brown tissues. PCR analysis demonstrated that beta 3-AR mRNA expression is not related to the UCP content of fat pads and that beta 3-AR expression is low. This study demonstrates the presence of great proportions of brown adipocytes in adipose tissue and the heterogeneity of the fat pads in baboons. The lack of a metabolic effect of beta 3-agonists combined with the weak expression of beta 3- AR mRNAs raise the question of the role of beta 3-ARs in adipose tissues of primates.

This article has been cited by other articles:

				S. Collins, W. Cao, and J. Robidoux Learning New Tricks from Old Dogs: {beta}-Adrenergic Receptors Teach New Lessons on Firing Up Adipose Tissue Metabolism Mol. Endocrinol., September 1, 2004; 18(9): 2123 - 2131. [Abstract] [Full Text] [PDF]

				Y. Li, J. R. Knapp, and J. J. Kopchick Enlargement of Interscapular Brown Adipose Tissue in Growth Hormone Antagonist Transgenic and in Growth Hormone Receptor Gene-Disrupted Dwarf Mice Experimental Biology and Medicine, February 1, 2003; 228(2): 207 - 215. [Abstract] [Full Text] [PDF]

				E. Jequier and L. Tappy Regulation of Body Weight in Humans Physiol Rev, April 1, 1999; 79(2): 451 - 480. [Abstract] [Full Text] [PDF]

				P. Laharrague, D. Larrouy, A.-m. Fontanilles, N. Truel, A. Campfield, R. Tenenbaum, J. Galitzky, J. X. Corberand, L. Pénicaud, and L. Casteilla High expression of leptin by human bone marrow adipocytes in primary culture FASEB J, June 1, 1998; 12(9): 747 - 752. [Abstract] [Full Text]

				H. F. Urbanski and K.-Y. F. Pau A Biphasic Developmental Pattern of Circulating Leptin in the Male Rhesus Macaque (Macaca mulatta) Endocrinology, May 1, 1998; 139(5): 2284 - 2286. [Abstract] [Full Text] [PDF]

				D. S. Meyers, S. Skwish, K. E. J. Dickinson, B. Kienzle, and C. M. Arbeeny {beta}3-Adrenergic Receptor-Mediated Lipolysis and Oxygen Consumption in Brown Adipocytes from Cynomolgus Monkeys J. Clin. Endocrinol. Metab., February 1, 1997; 82(2): 395 - 401. [Abstract] [Full Text] [PDF]