FIGURE 4.

Impacts of a maximally effective Ca²⁺_o concentration on time-dependent CaR^T888 phosphorylation and Ca²⁺_i mobilization. A, representative Western blot showing CaR^pT888 (i) and total CaR (ii) immunoreactivity following exposure to 5 mm Ca²⁺_o for different lengths of time up to 20 min. Quantification of the changes in CaR^T888 phosphorylation expressed in arbitrary (arb.) units for the 160-kDa CaR band is shown in panel iii (n = 5). **, p < 0.01, ***, p < 0.001 versus t₀; +, p < 0.05, ++, p < 0.01 versus 1-min treatment by repeated measures ANOVA (Tukey post test). B, representative trace showing Ca²⁺_i changes in a single cell (gray) or global cluster of cells (black) in response to 5 mm Ca²⁺_o (n = 3).