title: The associations acetylcholine-eserine and acetylcholine-morphine studied on the frog rectus abdominis muscle.
abstract: The interaction of morphine and eserine with acetylcholine (Ach) on frog rectus abdominis muscle was studied. Both eserine and morphine potentiate the effects of exogenous Ach and this effect is certainly not due to the anticholinesterase action of the two drugs. Morphine is less effective than eserine in potentiating the response of the muscle to the Ach introduced in the organ-bath. The synergisms Ach-eserine and Ach-morphine are synergisms with potentiation: it is concluded that eserine and morphine in amphibian muscle interact with specific receptors. These binding sites are different from both the esterase and the ACh binding sites of the cholinergic receptor but appear to influence its function.
mesh_terms: D000009:Abdominal Muscles / Q000187:drug effects / Q000378:metabolism; D000109:Acetylcholine / Q000494:pharmacology*; D000818:Animals; D004305:Dose-Response Relationship, Drug; D004357:Drug Synergism; D009020:Morphine / Q000494:pharmacology*; D009119:Muscle Contraction / Q000187:drug effects; D009132:Muscles / Q000378:metabolism*; D010830:Physostigmine / Q000494:pharmacology*; D011896:Rana temporaria
chemical_list: D009020:Morphine; D010830:Physostigmine; D000109:Acetylcholine