Table 4. Table Showing the Inhibitory Effect of 44 Compounds Measured in the Initial Screens^a.

^aFive categories were determined: 50% inhibition observed below 1 μM, 50% inhibition between 1 and 10 μM, 50% inhibition above 10 μM, and no effect on transport (colored dark gray). In addition, several compounds were identified as transport activators (colored blue).