Fig. 5

Fig. 5

Trpm7 deleted SAN exhibit impaired automaticity with slowed diastolic Ca²⁺ rise. Ca²⁺ transients measured by high-speed line-scanning confocal microscopy in (A) WT SAN and (B) KO^αMHC-Cre SAN under basal conditions (Top) and after stimulation with ISO: 2 nM (Middle) and 100 nM (Bottom). (C) Mean Ca²⁺ transient frequency and (D) Ca²⁺ transient length in WT SAN compared with KO^αMHC-Cre SAN under basal conditions and after stimulation with 2 nM and 100 nM ISO. (E) Representative Ca²⁺ transients from WT (Left) and KO^αMHC-Cre (Right) showing the slope of diastolic Ca²⁺ rise (Ca²⁺ ramp). (F) Mean slope of the diastolic Ca²⁺ ramp in WT and KO^αMHC-Cre under increasing ISO concentrations. *P < 0.05, **P < 0.01.