Figure 2. Functional studies of disease-related CaSR mutations in individual HEK293 cells.

The various panels show representative oscillation patterns from single cells. HEK-293 cells transfected with CaSR or one of its mutants were loaded with Fura-2 AM for 15 min. [Ca²⁺]_i was assessed by monitoring emission at 510 nm with excitation alternately at 340 or 380 nm as described in Methods. Each experiment was carried out with or without 5 mM L-Phe and began in Ca²⁺-free Ringer's buffer (10 mM HEPES, 140 mM NaCl, 5 mM KCl, and 1.0 mM MgCl₂, pH 7.4), followed by stepwise increases in [Ca²⁺]_o until [Ca²⁺]_i reached a plateau (up to 30 mM [Ca²⁺]_o).