Fig. 7. Li⁺ affects subcellular distribution of IP₃R_N. (A) Immuno-fluorescence analysis of cells grown in media with 1 µM [Ca²⁺]_o and incubated with 25 mM LiCl for the times indicated, followed by immuno-labeling with IP₃R_N-specific Abs (left panels, -IP₃R_N) or Abs against V-type H⁺-ATPase (right panels, -vATPase). The IP₃R_N is selectively affected, with a maximal outcome after 3 hours, resulting in reduced ORS-staining and increased diffuse background fluorescence. As a control, cells were treated with NaCl for 3 hours (bottom panels) with no remarkable effect. (B) Contraction periods of contractile vacuoles of cells treated with LiCl for 3 hours are significantly prolonged (black bar) when compared to control cells (white bar, P<0.001) or to cells treated with NaCl (light gray bar, P<0.001). Contraction periods of cells incubated with NaCl are only slightly prolonged in comparison to control cells, with weak significance (P=0.014 for NaCl to untreated control). Three hours after treatment with LiCl, contraction periods return to control levels when cells are transferred to culture medium (dark gray bar).