Fig. 10. Acidification of oc/oc mutant pancreatic islet cells, and insulin secretion in ßHC9 cells following treatment with bafilomycin A. (A) Wild-type and oc/oc islets were dispersed with trypsin and stained with LysoTracker. After fixation with 4% paraformaldehyde in PBS (pH 7.4), the cells were mounted for observation. Bar, 10 µm. (B) LysoTracker staining of control ßHC9 (w/o Baf) cells or ßHC9 cells after treatment for 1 hour with bafilomycin A (10 nM). Bar, 10 µm. (C) Insulin secretion of ßHC9 cells stimulated by 25 mM glucose after treatment for 1 hour with bafilomycin A (10 nM) as described under `Materials and Methods'. Means ± s.d. of triplicate observations in a single representative experiment are shown here. Broken line and open circle, control cells; solid line and filled square, cells treated with bafilomycin A.