Desensitization of β-adrenergic receptor-coupled adenylate cyclase activity: differences following exposure of cells to two full agonists

摘要: Abstract The effects on the β-adrenergic receptors of intact L6 muscle cells exposure to agonists were investigated. Treatment with isoproterenol decreased GTP-, isoproterenol-, and zinterol-stimulated adenylate cyclase activities, whereas zinterol only isoproterenol- activities. Although these two full GTP-stimulated activity different, time courses for development reversal similar. decrease in agonist-stimulated observed membranes prepared from previously exposed or was due both an increase concentration agonist required half-maximal activation a maximum level activation. No fluoride- manganese-stimulated activities following either agonist. Decreases also epinephrine, Cc-25, fenoterol, norepinephrine, terbutaline, metaproterenol, but not incubation dobutamine salmefamol. results suggest that interacting same receptor can induce different changes components system. Desensitization may result modification receptor, be alterations guanine nucleotide-binding protein receptor.