The effects of levosimendan on [Ca2+]i in guinea-pig isolated ventricular myocytes.
Ca2+-sensitising agents offer a new approach to the treatment of congestive heart failure. This study examined the effects of the Ca2+-sensitising agent, levosimendan, on contraction and [Ca2+]i in guinea-pig ventricular myocytes. Levosimendan 100 nM produced an increase in cell shortening without affecting the [Ca2+]i transient or the Ca2+ content of the sarcoplasmic reticulum. 1 microM levosimendan increased the rate of decay of the [Ca2+]i transient and increased the Ca2+ content of the sarcoplasmic reticulum. These results suggest that at therapeutically relevant concentrations levosimendan can produce a significant inotropic effect without affecting [Ca2+]i but at higher concentrations may also inhibit phosphodiesterase.
Lancaster
M K
MK
Department of Veterinary Preclinical Sciences, University of Liverpool, UK.
Cook
S J
SJ
D000818:Animals; D002118:Calcium / Q000378:metabolism*; D002316:Cardiotonic Agents / Q000494:pharmacology*; D006168:Guinea Pigs; D006352:Heart Ventricles / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D006835:Hydrazones / Q000494:pharmacology*; D066298:In Vitro Techniques; D011724:Pyridazines / Q000494:pharmacology*; D012519:Sarcoplasmic Reticulum / Q000187:drug effects* / Q000378:metabolism; D000077464:Simendan; D013599:Systole / Q000187:drug effects*
D002316:Cardiotonic Agents; D006835:Hydrazones; D011724:Pyridazines; D000077464:Simendan; D002118:Calcium