TISSUE SWELLING AND INTRACELLULAR PH IN THE CA1 REGION OF ANOXIC RAT HIPPOCAMPUS

The fluorescent dye BCECF was used to simultaneously determine the int racellular pH (ratio 495:450 nm) and changes in relative tissue volume (fluorescence at the 450 nm isosbestic wavelength) in rat hippocampal slices. Anoxia in the presence of glucose caused tissue swelling and subsequent intracellular acidosis after a short and small transient al kaline peak. Reoxygenation reversed tissue swelling only partly and en ded in persistent tissue swelling. The intracellular pH was initially further acidified before restoration to the normoxic intracellular pH occurred. Omitting glucose during anoxia caused similar but more marke d changes of relative tissue volume. However, acidosis during anoxia w as less marked and subsequently converted to alkalosis. Reoxygenation also caused initial acidification but the intracellular pH was not com pletely restored afterwards.