Acetylcholine's inhibitory effect on the calcium-dependent depolarization in the heart cells of a reptile (Lacerta sicula campestris). Preliminary notes.
The results of experiments performed with high - K+ solutions suggest that in the lizard atrial cells Ach normally displays its negative inotropic effects by a double mechanism = an "indirect" inhibition, mediated by the increase of the membrane permeability to K+ ions; and a "direct" inhibition of the Ca- carried slow inward current. In the ventricular fibres there isn't a direct-effect of this drug, under normal conditions.
D000109:Acetylcholine / Q000494:pharmacology*; D000200:Action Potentials / Q000187:drug effects; D000818:Animals; D002118:Calcium / Q000037:antagonists & inhibitors* / Q000378:metabolism; D003864:Depression, Chemical; D006321:Heart / Q000502:physiology; D008116:Lizards / Q000502:physiology*; D009200:Myocardial Contraction / Q000187:drug effects; D009206:Myocardium / Q000378:metabolism*
D000109:Acetylcholine; D002118:Calcium