title: In vitro interaction of ACTH with rat brain muscarinic receptors.
abstract: ACTH-(1-24) inhibits the in vitro binding of the muscarinic antagonist [3H]QNB to membranes from rat brain. The magnitude of inhibition is dependent on the concentration of ACTH-(1-24). Kinetic analysis indicates a pure competitive inhibition which is suggestive of a reversible interaction of ACTH with muscarinic receptors. A mechanism involving an interaction of ACTH-(1-24) with the phospholipid core of the receptors is suggested. Structure activity studies point to a relation with reported effects of intracerebroventricularly administered ACTH on the turnover rate of acetylcholine and the ACTH-induced stretching and yawning syndrome.
mesh_terms: D000324:Adrenocorticotropic Hormone / Q000494:pharmacology*; D000818:Animals; D001667:Binding, Competitive; D001921:Brain / Q000378:metabolism*; D002462:Cell Membrane / Q000378:metabolism; D003366:Cosyntropin / Q000494:pharmacology*; D007700:Kinetics; D008297:Male; D011813:Quinuclidinyl Benzilate / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains; D011976:Receptors, Muscarinic / Q000187:drug effects / Q000378:metabolism*
chemical_list: D011976:Receptors, Muscarinic; D003366:Cosyntropin; D011813:Quinuclidinyl Benzilate; D000324:Adrenocorticotropic Hormone