Figure 7.
Sodium dependence of DA transport and DA protection from MTSET. For protection (■), cells were treated with 0.25 mM MTSET for 10 min in the presence of 1 μM DA and the indicated concentration of Na+. The extent of protection is expressed as (AM−DA−AM)/(AC−AM), where AC is the control activity, AM is the activity after MTSET treatment, and AM-DA is the activity after MTSET treatment in the presence of DA. For transport (○), uptake of 1 μM DA was measured as described in Methods.