Toy Figures Beta3-Adrenoceptors are involved in the control of catecholamine-induced lipolysis in rodent adipose tissues.The expression and function of human beta3-adrenoceptors were investigated in subcutaneous white adipocytes of young healthy women.In these cells, beta3-adrenoceptor mRNAs represent 20% of total amount of beta-adrenoceptor transcripts and less than half of beta1-adrenoceptor transcripts.
Among beta3-agonists known to stimulate beta3-adrenoceptor-mediated lipolysis in rodent fat cells, only CGP12177 was able to mediate such activity in human fat cells.In in vitro lipolysis experiments and in situ microdialysis studies, CGP12177 had a 4- to 5-times lower lipolytic efficacy than isoprenaline, a nonselective beta-adrenoceptor agonist.CGP12177-induced lipolysis was antagonized in vitro by bupranolol, a beta-adrenergic antagonist potent on rodent beta3-adrenoceptors but not by nadolol, a beta1- and beta2-adrenoceptor antagonist.
The in vitro blockade of isoprenaline-stimulated lipolysis by nadolol showed that the agonist acted solely via beta1- and beta2-adrenoceptors.Isoprenaline and CGP12177 were able to increase the nutritive blood flow suggesting an interaction of these molecules with receptors present in Body Sunscreen adipose tissue vessels.In conclusion, beta3-adrenoceptors are expressed in human subcutaneous white adipocytes but do not significantly contribute to isoprenaline-induced lipolysis.