Fig. 4.

Nicotine accumulation in intact and isolated granules of A549 cells. Nicotine accumulation within intact and isolated granules ([Nicotine]_granular) increased in a time- and dose-dependent manner. A: both 1 μM (●; n ≥ 24) and 10 μM (○; n ≥ 60) nicotine exposure resulted in similar rate of accumulation in intact granules of A549 cells. B: exposure of isolated granules to nicotine 1 μM (●; n ≥ 15) and 10 μM (○; P < 35) resulted in accelerated accumulation similar to intact granules. Inset displays equivalent fluorescent yields of a nicotine standard made in intracellular solution. Data were presented as means ± SD; n represents the number of cells or granules investigated in the experiments.