“…Interestingly, Tadros et al (Tadros et al, 2002) showed that transfection of rat cardiomyocytes with antisense oligonucleotides to NCX resulted in delayed relaxation after caffeine-induced contracture (in the absence of changes in other Ca 2+ -handling proteins), but overall contractile activity in these cells was not significantly altered in the presence of physiological levels of extracellular Ca 2+ . In other studies of transgenic mouse cardiomyocytes, rates of contraction and relaxation have been found to increase but the effect is often small and the results of studies vary (Cross et al, 1998;Hryshko, 2002).…”