Molecular mechanisms underlying regional variations of catecholamine-
induced lipolysis in rat adipocytes.
Tavernier, Genevi[grave]eve, Jean Galitzky, Philippe Valet, Anne Remaury,
Anne Bouloumi[acute]e, Max Lafontan, and Dominique Langin.
Institut National de la Sant[acute]e et de la Recherche M[acute]edicale
Unit[acute]e 317, Institut Louis Bugnard, Centre Hospitalier Universitaire de
Rangueil, 31054 Toulouse Cedex, France
APStracts 2:0019E, 1995.
The mechanisms underlying catecholamine control of lipolysis were
studied in rat white adipocytes from epididymal, retroperitoneal and
subcutaneous fat depots. A lower sensitivity of subcutaneous
adipocytes to selective [beta]3-adrenoceptor agonists was shown when
compared to internal adipocytes. [beta]3-adrenoceptor mRNA levels were
lower in subcutaneous adipocytes. A decreased [beta]1/[beta]2-adrenoceptor
mediated lipolysis was also observed in these adipocytes and the
number of [beta]1/[beta]2-adrenoceptors was lower than in the internal
adipocytes. The number of [alpha]2-adrenoceptors was higher in subcutaneous
adipocytes without a marked difference in [alpha]2-adrenoceptor mediated
antilipolysis between the depots. Subcutaneous adipocytes were also
characterized by a lower maximal lipolytic response to drugs acting
at different levels of the lipolytic cascade suggesting differences
at the post-receptor level. Lower hormone-sensitive lipase activity
and mRNA levels in subcutaneous adipocytes were in agreement with the
lipolysis data. These results suggest that the pattern of expression
of the genes of the lipolytic pathway varies with the anatomical
location of the fat depot.
Received 3 October 1994; accepted in final form 27 January 1995.
APS Manuscript Number E412-4.
Article publication pending Am. J. Physiol. (Endocrinol. Metab.).
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 25 February 1995.