Figure 2.

Na⁺and temperature dependence of 5-HT protection of I172C. Cells expressing SERT I172C were incubated in PBS (●) or Na⁺-free (NMDG) PBS solution (○) containing 0.1 mM MTSET for 10 min at 22°C (left axis), or 0.3 mM MTSET at 2–4°C (■, right axis) in the presence of the indicated concentrations of 5-HT. Cells were rinsed with PBS and assayed for transport in PBS at 22°C. The rate of inactivation was expressed as a pseudo first-order rate constant, assuming a simple exponential decay of the transport activity.