@article{article_399978, title={Investigation of the cellular mechanisms of actions of digoxin and monensin by using guinea-pig papillary muscles}, journal={Journal of Applied Biological Sciences}, volume={3}, pages={1–5}, year={2009}, url={https://izlik.org/JA38YS29FP}, author={Üstün, Ramazan and Meral, İsmail}, keywords={Monensin,digoxin,guinea pig,papillary muscle}, abstract={<p>This experiment was carried out to determine the possible mechanism of actions of monensin and digoxin by using guinea-pig papillary muscles. A total of 120 papillary muscles obtained from 60 guinea-pigs were used. Three treatment groups; control (%0,1 ethanol), monensin (10 μmol/l) and digoxin (3 μmol/l) were compared in normal, Na+-free, Ca2+-free, and thapsigargin-added Krebs solutions. It was found that both digoxin and monensin caused a positive inotropic effect in normal and Ca2+-free Krebs solutions. Although monensin produced a positive inotropic effect in thapsigargin-treated papillary muscles, digoxin did not show a positive inotropic effect. Because papillary muscles in Na+ -free Krebs solution showed spontaneous contractions, trusted results were not obtained in Na+ -free medium. It is concluded that monensin produces a positive inotropic effect by depending on both extracellular Ca2+ and Ca2+ released from the sarcoplasmic reticulum (SR). Digoxin, on the other hand, produces its effect by depending on the Ca2+ released from SR. </p>}, number={3}