Store-Operated Calcium Entry in Mouse Cardiomyocytes

Abstract

The fluorescent dye fura-2 AM was employed to record activation of Ca²⁺ entry in response to a decrease in Ca²⁺ concentration in the endoplasmic reticulum. Using whole-cell voltage clamp technique, we revealed Ca²⁺ currents with an amplitude of 0.46±0.13 pA/pF that passed through selective channels with current-voltage characteristics similar to those of classical store-operated CRAC channels. These currents were sensitive to 2-APB (50 μM), an inhibitor of store-operated channels. The data suggest that store-operated calcium entry is a characteristic feature of mature ventricular cardiomyocytes. Pathological alterations in store-operated Ca²⁺ entry can be implicated in the development of heart diseases.