Figure 7.

Changes of intracellular pH caused by a 10-min treatment with butyric acid. Cell samples were perfused with one-half-concentrated, phosphate-free culture liquid at pH_ext = 3.8. After a 15-min period of adaptation in which neither pH_ext nor cytoplasmic/nuclear pH changed significantly, the first image was scanned (t = 0) and the perfusion medium was replaced by 2 mm sodium butyrate in one-half-concentrated, phosphate-free culture liquid pH adjusted to 3.8 with HCl. After another 10 min the perfusion liquid was changed back to the first, butyrate-free medium.