FIGURE 6.
At a 1:1 ratio, Cav1.233L channels yield a dominant negative effect on the reference cardiac Cav1.2 channels. A, single-cell RT-PCR was performed after each patching experiment. The upper bands represent exon 33L, whereas lower bands represent the reference channel. Data from cells with unequal transfection were discarded. B, tail current density (pA/pF) was calculated in 1.8 mm Ca2+ from cells expressing the reference cardiac Cav1.2 channels together with the Cav1.233L channels (●, n = 7) or pcDNA3 vector (○, n = 9). C, a sample trace at +50-mV test pulse illustrates the measurement of gating current, indicated by an arrow. D, summary of the gating currents (femtocoulombs/pF (fC/pF)) measured from 33L channel or pcDNA3 transfected cells. *, p = 0.0063, Student's t test.