THE EFFECTS OF LEVOSIMENDAN ON [CA2-PIG ISOLATED VENTRICULAR MYOCYTES(](I) IN GUINEA)

Ca2+-sensitising agents offer a new approach to the treatment of conge stive heart failure. This study examined the effects of the Ca2+-sensi tising agent, levosimendan, on contraction and [Ca2+](i) in guinea-pig ventricular myocytes. Levosimendan 100 nM produced an increase in cel l shortening without affecting the [Ca2+](i) transient or the Ca2+ con tent of the sarcoplasmic reticulum. 1 mu M levosimendan increased the rate of decay of the [Ca2+](i) transient and increased the Ca2+ conten t of the sarcoplasmic reticulum. These results suggest that at therape utically relevant concentrations levosimendan can produce a significan t inotropic effect without affecting [Ca2+](i) but at higher concentra tions may also inhibit phosphodiesterase. (C) 1997 Elsevier Science B. V.