Figure 5.

Gd³⁺ sensitive (TRP) cation channels generate Ca²⁺ sparks in old VSMCs. (a), Ca²⁺ fluorescence images of a Fluo‐4‐AM–loaded VSMC from an old mouse and time course of Ca²⁺ fluorescence changes in the cellular ROI (upper panel). Cell boundary is marked with dashed line. (b), same as (a) but with a cell incubated with Cd²⁺ (200 µM). (c), same as (a) but with Ni²⁺ (50 µM) following Cd²⁺ treatment. (d), same as (a) but with Gd³⁺ (100 µM) following Cd²⁺+ Ni²⁺ treatment. (e, f), summary of the results. Ca²⁺ spark frequency (e) and fraction of cells producing Ca²⁺ sparks (f) in cells (n = 66), in cells incubated with Cd²⁺ (n = 69), in cells incubated with Cd²⁺+ Ni²⁺ (n = 61), and in cells incubated with Cd²⁺+ Ni²⁺+ Gd³⁺ (n = 86). Cells were isolated from 4 old mice in each group; 15–30 cells were recorded and analyzed from each mouse. *, p < .05. n.s., not significant