Figure 4. Other NO donors do not inhibit the β-adrenergic stimulation of I_Ca,L in rat ventricular myocytes.

A, a myocyte was first exposed to control intracellular and extracellular solutions. Applications of Iso (10 nM) and SIN-1 (100 μM) are indicated by the horizontal lines. Current traces on top were recorded at the times indicated by the corresponding letters on the main graph. The dotted line indicates the zero-current level. B, summary of the effects of three NO donors (SNAP, SIN-1, SPNO, at 100 μM) on I_Ca,L in the presence of either 1 nM (▪) or 10 nM Iso (□). The effects of NO donors on I_Ca,L are presented as percentage variations from the amplitude of the Iso-stimulated I_Ca,L. Bars are the means and lines are the s.e.m. of the number of experiments indicated near the bars.