Figure 6.
AITC-induced increases in contractile function and [Ca2±]i occur independently of PKA in CMs. Overlays of fractional shortening and [Ca2+]i peak amplitudes in electrically-paced CMs illustrating the effects of AITC (100 µmol/L) in the presence and absence of PKI 14–22 (100 nmol/L) are depicted in panels A and B, respectively. Summarized data for parameters measuring contractile function are depicted in panels C (fractional shortening), E (maximum velocity of shortening) and G (maximum velocity of relengthening). Summarized data analyzing [Ca2+]i dynamics are depicted in panels D ([Ca2+]i peak amplitude), F (time to peak [Ca2+]i) and H ([Ca2+]i decay). Results are expressed as percent of steady-state baseline control (Ctrl) value set at 100%. Individual [Ca2+]i traces were smoothed using the Savitzky-Golay filter to increase the signal-to-noise ratio. N.S. = not statistically significant. * P < 0.05 compared with Ctrl. n = 18 cells from 6 hearts.