Inhibitory alpha-2 adrenoceptors in human adipose tissue
Lafontan, M.; Berlan, M.
International Journal of Obesity 5(6): 651-657
1981
ISSN/ISBN: 0307-0565 PMID: 6119296 Document Number: 181004
Selected alpha-agonists and alpha-antiagonists were used in in-vitro incubations to study the type of alpha-receptor responsible for lipolysis inhibition in human adipose tissue. Clonidine was the most potent of 5 agonists tested for inhibition of theophylline-induced lipolysis. The relative order of potency was consistent with the classification of agonists described for the presynaptic alpha-2 receptor. Yohimbine was the most potent of 5 alpha-antagonists tested for antagonizing clonidine inhibition of theophylline-induced lipolysis, with the relative order of potency consistent with an alpha-2 type receptor. The presence of clonidine binding sites in human fat cell membranes having the characteristics of alpha-2 adrenoceptors also was observed. The results show that the alpha-adrenergic receptor inhibiting human fat cell lipolysis is of the alpha-2 type. (wz)