phosphatase Inhibition

Dynamic modulation of Ca2+ signaling by phosphatase inhibition. Isolated mouse ventricular myocytes were maintained in voltage clamp mode and passively loaded with Ca indicator dye, Indo-1. Shown is the voltage dependence of the [Ca2+]i transient and whole cell Ca2+ current, ICa, before and after application of phosphatase inhibitor, calyculin A. Note that inhibition of phosphatases evokes a profound increase in both Ca signals. This reveals the functional significance of phosphatases in controlling cardiac cell function.