Fig. 5. Effects of SKF-96365 on norepinephrine (NE)- and KCl-induced increases in force and R340/380in the presence of ryanodine (+ryanodine). (A ) Examples of steady-state (i.e. , maximal) effects of SKF-96365 on the responses to either norepinephrine (left ) or KCl (right ). (B ) Analyzed data (left , force; right , R340/380) (n = 4). *P < 0.05 versus control (100%) within each group. **P < 0.01 versus control (100%) within each group. The IC50values for the inhibitions of norepinephrine-induced increases in force and R340/380were 1.8 and 2.5 μm, respectively, whereas those for the inhibitions of KCl-induced increases in force and R340/380were 1.3 and 5.3 μm, respectively.