Caffeine altered frequency, rise and decay times of Ca2+ sparks. (A) Original recordings of Ca2+ sparks in the absence (top trace), presence (middle trace) and washout (bottom trace) of 1 mM caffeine. Numbers beside transients indicate sparks. (B) Caffeine increased the frequency, rise and decay time of Ca2+ sparks but had no effect on Ca2+ spark amplitude. Recordings in the presence of caffeine were made at 10, 40 and 70s after drug application and recordings during washout were made at 10, 40 and 70s after termination of drug application. Time control experiments revealed that Ca2+ spark frequency, amplitude, rise time and time to half-decay were reasonably stable for nine 5 s line scans spread over 225 s.
Krishnamoorthy et al. BMC Physiology 2011 11:15 doi:10.1186/1472-6793-11-15