Figure 1. Ca²⁺ uptake by CHO cells expressing the Δ(241–680) mutant of NCX.

Cells were pre-treated with ATP + Tg, and with 1 μg ml⁻¹ gramicidin in either 10/130 or 100/40 Na/K-PSS containing 0.3 mm EGTA as described in Methods. Ca²⁺ uptake was initiated by superfusing 4–5 ml of 0.1 mm Ca²⁺ in 10/130 or 100/40 Na/K-PSS. The results are representative of experiments conducted on more than 3 separate occasions.