Figure 10.
Confocal microscopic analysis of sst2A receptor and Golgi, endosomal, or ER markers immunoreactivity in fixed neurons treated with octreotide. Neurons were transfected with the plasmid encoding the wild-type receptor (sst2A-WT), treated with octreotide, and fixed at different times after initiation of the treatment. After fixation, localization of sst2A receptors and various intracellular markers was revealed by immunocytochemistry. After 5 min of agonist treatment, clusters of internalized receptors colocalize with transferrin receptor and EEA1, two markers of early endosomes. Twenty minutes after the addition of octreotide, sst2A receptors do not colocalize with the late endosome/lysosome marker LAMP-1 but overlap with trans-Golgi markers syntaxin 6 and TGN38. No colocalization was observed with the cis-Golgi marker GM 130 or the ER marker PDI. Scale bars: 5 μm; except for sst2A-WT/GM130 and sst2A-WT/Lamp-1, 3 μm.