Different Na+/K+-ATPase signal pathways was involved in the increase of [Ca2+]i induced by strophanthidin in normal and failing isolated guinea pig ventricular myocytes.

Aim: To determine whether different Na+/K+-ATPase signal transduction pathways have positive inotropic effects on normal ventricular myocytes (NC) and failing ventricular myocytes (FC), and are involved in an increase of [Ca2+]i induced by strophanthidin (Str).

Methods: A guinea pig model of congestive heart failure was made by constricting descending aorta. The left ventricular myocytes were enzymatically isolated.

Effects of strophanthidin on intracellular calcium concentration in ventricular myocytes of guinea pig.

Effect of strophanthidin (Str) on intracellular calcium concentration ([Ca2+]i) was investigated on isolated ventricular myocytes of guinea pig. Single ventricular myocytes were obtained by enzymatic dissociation technique. Fluorescent signal of [Ca2+]i was detected with confocal microscopy after incubation of cardiomycytes in Tyrode' s solution with Fluo3-AM.