Fig. 3. ET enhances nuclear CaTs. (A) 2D Fluo-4 fluorescence images of an atrial myocyte during an electrically stimulated CaT before (Control) and during exposure to 10 nM ET. Bar, 20 µm. (B) Cytoplasmic (black traces) and nuclear (red traces) CaTs recorded before (left) and during (right) ET treatment. (C) The means ± s.e.m. of ET-induced changes in systolic [Ca²⁺]. Nuc/Cyto, ratio of nuclear to cytoplasmic [Ca²⁺]. (D) ET-induced changes in CaT kinetics. (Left) Normalised original CaTs before and during (blue) ET exposure. (Right) The means ± s.e.m. of time-to-peak and the time constant for CaT decay. The data were obtained from 24 atrial myocytes.