Agonist‐induced desensitisation of β 3 ‐adrenoceptors: Where, when, and how?

β3 -Adrenoceptor agonists have proven useful in the treatment of overactive bladder syndrome, but it is not known whether their efficacy during chronic administration may be limited by receptor-induced desensitisation. Whereas the β2 -adrenoceptor has phosphorylation sites that are important for desensitisation, the β3 -adrenoceptor lacks these; therefore, it had been assumed that β3 -adrenoceptors are largely resistant to agonist-induced desensitisation. While all direct comparative studies demonstrate that β3 -adrenoceptors are less susceptible to desensitisation than β2 -adrenoceptors, desensitisation of β3 -adrenoceptors has been observed in many models and treatment settings. Chimeric …