[2 unusual responses of the myocardium in the frog Rana temporaria to acetylcholine].
When studying seasonal variations in acetylcholine sensitivity of isolated frog ventricle, two forms of unusual responses have been observed: 1) tonic response induced by supermaximal concentration of acetylcholine, and 2) double response to the increasing acetylcholine concentrations with two different threshold and maximum doses (KAch values differ by 1-2 orders). The tonic response is blocked by mytolone. Both effects are of a seasonal nature. Similar pattern of these reactions in frogs and molluscs suggests a possibility of restoration of evolutionary more ancient form of cholinergic response, hormonal influences being involved into this process.
Nistratova
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SN
D000109:Acetylcholine / Q000494:pharmacology*; D000818:Animals; D001285:Atropine / Q000494:pharmacology; D002316:Cardiotonic Agents / Q000494:pharmacology; D002800:Cholinesterase Inhibitors / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D006321:Heart / Q000187:drug effects*; D066298:In Vitro Techniques; D000644:Quaternary Ammonium Compounds / Q000494:pharmacology; D011896:Rana temporaria; D012621:Seasons
D002316:Cardiotonic Agents; D002800:Cholinesterase Inhibitors; D000644:Quaternary Ammonium Compounds; D001285:Atropine; D000109:Acetylcholine; C004991:benzoquinonium
O dvukh neobychnykh otvetakh miokarda liagushki Rana temporaria na atsetilkholin.