Partitioning and Exocytosis of Secretory Granules during Division of PC12 Cells
Figure 9
Analysis of regulated exocytosis in mitotic PC12 cells. Synchronized PC12 cell populations were incubated in growth medium supplemented with either 55 mM KCl ((A), (C), (E), (G), (I)) or 55 mM NaCl ((B), (D), (F), (H), (J)) and processed for immunofluorescence staining of surface-associated SgII (red) and DNA-staining (green). Interphase cells ((C) and (D)) and dividing cells at different stages of mitosis displayed prominent SgII surface staining under stimulating conditions ((E), prophase, (G), metaphase, (I), anaphase) but not under control conditions ((F), prophase, (H), metaphase, (J), anaphase). Scale bars: images (A) and (B), 10 μm, (C) to (J), 5 μm. (K) Quantitative analysis of the signal intensity of the SgII surface staining revealed that 81 ± 11% (±SD) of the interphase and 67 ± 26% (±SD) of the metaphase cells displayed a signal intensity above the background value determined under control conditions. In addition, the signal intensity of the SgII surface staining of metaphase cells was on average 61 ± 13% (±SD) of the mean intensity of interphase cells. For the evaluation, interphase and metaphase cells (, resp.) were randomly chosen from two independent experiments.
