title: beta-Adrenergic receptor regulation by agonists and membrane depolarization in rat brain slices.
abstract: Rat cerebral cortex slices exposed to (-)-isoproterenol and then washed accumulated significantly less cyclic AMP when rechallenged with isoproterenol than did control slices. The isoproterenol-induced desensitization was associated with a concurrent reduction in [3H]dihydroalprenolol membrane binding but with no change in the affinity of [3H]dihydroalprenolol or isoproterenol for the binding sites. beta-Adrenergic receptor desensitization was rapidly reversed by slice depolarization with high-[K+] buffers, batrachotoxin, grayanotoxin, or veratridine, even in the continued presence of isoproterenol. Restoration of binding by grayanotoxin was prevented by tetrodotoxin or by removing Na+ from the buffer. These data demonstrate partial participation of the membrane receptor in beta-adrenergic desensitization of rat brain slices and suggest that brain beta-adrenergic receptors, like cholinergic receptors in skeletal muscle and alpha-adrenergic receptors in rat parotid, are regulated in part by membrane voltage.
mesh_terms: D000818:Animals; D001667:Binding, Competitive; D002462:Cell Membrane / Q000502:physiology*; D002540:Cerebral Cortex / Q000187:drug effects / Q000378:metabolism*; D000242:Cyclic AMP / Q000378:metabolism; D004837:Epinephrine / Q000494:pharmacology; D066298:In Vitro Techniques; D007545:Isoproterenol / Q000494:pharmacology*; D007700:Kinetics; D008297:Male; D009638:Norepinephrine / Q000494:pharmacology; D011869:Radioligand Assay; D051381:Rats; D011941:Receptors, Adrenergic / Q000378:metabolism*; D011943:Receptors, Adrenergic, beta / Q000187:drug effects / Q000378:metabolism*
chemical_list: D011941:Receptors, Adrenergic; D011943:Receptors, Adrenergic, beta; D000242:Cyclic AMP; D007545:Isoproterenol; D009638:Norepinephrine; D004837:Epinephrine