title: Alpha- and beta-adrenergic and muscarinic cholinergic binding sites in the bladder and urethra of the rabbit.
abstract: The affinities of a number of alpha- and beta-adrenergic binding sites and muscarinic cholinergic binding sites in rabbit urethra and bladder have been determined, using specific radioligand receptor binding assays. There was a greater density of beta-binding sites than alpha-binding sites in the bladder, while, in the urethra, there was a greater density of alpha-binding sites than beta-binding sites. The number of alpha-binding sites was fourfold greater in the urethra, whereas there were fewer beta-binding sites in the urethra. There were fewer muscarinic binding sites in the urethra than in the bladder. The dissociation constant for [3H]dihydroalprenolol at the beta-binding site was 6.4 nM, for [3H]dihydroergocryptine at the alpha-binding site was 2.11 nM, and for 3H-labelled l-quinuclidinyl benzilate at the muscarinic binding site was 0.22 nM.
mesh_terms: D000818:Animals; D004082:Dihydroalprenolol / Q000378:metabolism; D004088:Dihydroergotoxine / Q000378:metabolism; D005260:Female; D066298:In Vitro Techniques; D008297:Male; D011813:Quinuclidinyl Benzilate / Q000378:metabolism; D011817:Rabbits; D011869:Radioligand Assay; D011941:Receptors, Adrenergic / Q000032:analysis*; D011942:Receptors, Adrenergic, alpha / Q000032:analysis*; D011943:Receptors, Adrenergic, beta / Q000032:analysis*; D011950:Receptors, Cholinergic / Q000032:analysis*; D011976:Receptors, Muscarinic / Q000032:analysis*; D014521:Urethra / Q000032:analysis* / Q000187:drug effects; D001743:Urinary Bladder / Q000032:analysis* / Q000187:drug effects
chemical_list: D011941:Receptors, Adrenergic; D011942:Receptors, Adrenergic, alpha; D011943:Receptors, Adrenergic, beta; D011950:Receptors, Cholinergic; D011976:Receptors, Muscarinic; D004088:Dihydroergotoxine; D004082:Dihydroalprenolol; D011813:Quinuclidinyl Benzilate