The effect of glu-dopa and nitecapone on dopamine level and distribution in LLCPK-1 cells. Confocal micrographs showing dopamine in LLCPK-1 cells. The images are represented by using a pseudo color scale, where blue is low intensity and yellow-red is high intensity. From left to right are control, untreated, glu-dopa (5 μM, 1 min), and nitecapone (5 μM, 20 min). By using the fluorophore Cy5 (excitation maximum, 649 nm; emission maximum, 670 nm), the effect of autofluorescence from glutaraldehyde fixation was reduced.