Fig. 5. The ET-induced enhancement of nuclear CaTs depends neither on the basal systolic [Ca²⁺] in the nucleus nor on the ratio of nuclear to cytoplasmic peak [Ca²⁺]. The ET-induced increase in peak [Ca²⁺] in the nucleus as a function of basal systolic [Ca²⁺] in the nucleus (A) or the ratio of nuclear to cytoplasmic systolic [Ca²⁺] (B) before ET exposure. The data are from 24 atrial myocytes challenged with ET.