3.3 Isorhamnetin prevented AngII-induced abnormal diastolic intracellular Ca2+ loading in HL-1 cells
HL-1 cells can self-generate spontaneous potentials without electrical stimuli; therefore, spontaneous Ca2+ waves can be observed with the use of Fluo-4 (Fig. 3A). The Ca2+amplitude (F/F0) was significantly higher in the AngII treatment group than in the isorhamnetin treatment group (Fig. 3C). In addition, AngII shortened the time to peak and decay time. In contrast, shortened time to peak and decay time were reversed by isorhamnetin treatment (Fig. 3D-E). Furthermore, during the depolarization process, AngII increased the occurrence of spontaneous abnormal Ca2+ waves more frequently than in the control, while isorhamnetin treatment suppressed them (Fig. 3A, G). These cellular electrophysiology results suggest that isorhamnetin reversed AngII-induced abnormal Ca2+ loading and aberrant diastolic Ca2+ activity.