Effects of Denervation on the Metabolism and the Response to Glucagon of White Adipose Tissue of Rats

Abstract

Unilateral denervation of the lumbar fat body in the rat resulted in a significant weight increase as compared with the controlateral normally innervated fat deposit This asymmetry in weight was already present after an overnight fast and became more pronounced after a 48-hour fast Denervation did not significantly affect basal glycerol production in vitro or basal free fatty acid (FFA) release but significantly increased adipose tissue glucose uptake. Glucagon-induced glycerol release was not affected by denervation; FFA release, in contrast, was significantly reduced. Glucose uptake by adipose tissue exposed to glucagon was also significantly increased. These results are interpreted as the consequence of a relative increase in (re) esterification of FFA by denervated adipose tissue. Such a mechanism is suggested to be responsible, at least in part, for the relative weight gain (or the reduced weight loss) of denervated adipose tissue. It sheds new light on the interrelationships between the innervation of adipose tissue and the action of physiologically circulating lipolytic hormones.

Key words

Rat - Adipose Tissue - Denervation - Lipolysis - Reesterification - Glucagon

1 Chargé de Recherches du Fond National de la Recherche Scientifique, Belgium.