Fig. 1. Intragranular localization of SgIII and CPE in rat pituitary mammotropes (A), rat pancreatic ß-cells (B), and mouse AtT-20 cells (C). CPE is visualized with 15 nm gold particles (A-C), SgIII is visualized with 10 nm immunogold particles (A-C). Insulin (B) and POMC-derived ACTH-containing peptides (C) are labeled with 5 nm immunogold particles. Note that SgIII (arrowheads) and CPE (arrows) are preferentially localized in the periphery of the SGs, and the SgIII and CPE are occasionally co-localized at the same sites in the periphery of the SGs (white arrows). Bar, 100 nm.