BETA-ADRENERGIC CONTROL OF LIPOLYSIS IN PRIMATE WHITE FAT-CELLS - A COMPARATIVE-STUDY WITH NONPRIMATE MAMMALS

The beta-adrenoceptor subtypes involved in the control of lipolysis in white fat cells of rat, dog, marmoset (Callithrix jacchus), baboon (Papio papio), macaque (Macaca fascicularis), and human were compared. In all species [H-3]CGP-12177 binding (up to 3 nM) indicated the existence of a homogeneous population of binding sites in fat cell membranes, and competition studies showed that beta(1)- and beta(2)-adrenoceptors were present. Selective beta(1)- or beta(2)-adrenoceptor agonists induced lipolysis. The efficiencies of isoproterenol and norepinephrine were similar. The use of selective beta(3)-adrenoceptor agonists revealed that BRL-37344 and CL-316243 were full agonists, whereas CGP-12177 and SR-58611A were partial agonists in rat and dog white fat cells. beta(3)-Agonists partially stimulated lipolysis in the marmoset, while CGP-12177 was weakly active in the baboon. In macaque and human fat cells, beta(3)-agonists were ineffective. The lipolytic effect of norepinephrine involves beta(1)- and/or beta(2)-adrenoceptors in baboon, macaque, and human. The baboon and macaque constitute valuable models for studying the beta-adrenergic control of lipolysis.