Figure 4.

Inhibition of bodipy-[Leu³¹, Pro³⁴]NPY internalization in Y₁-transfected HEK293 cells. Cells were incubated with PAO (20 μM) or sucrose (0.4 M) for 30 min at 37°C prior to the addition of 5 nM bodipy-[Leu³¹, Pro³⁴]PPY for a further 40 min. Fluorescent labeling was examined by confocal microscopy. Following incubation with either drug, the bulk of the fluorescent ligand remains associated with the cell surface. In cells pretreated with sucrose, a few intracytoplasmic endosomes are visible, but considerably less than in untreated cells (compared with Figure 2 at the same time point). Scale bar: 8 μm.