HYDROGEN-ION COMPARTMENTATION DURING AND FOLLOWING CEREBRAL-ISCHEMIA EVALUATED BY P-31 NMR-SPECTROSCOPY

Two peaks were observed in the inorganic phosphate region in P-31 NMR spectra obtained during and shortly after incomplete forebrain ischemi a induced in rats under normoglycemic conditions. Pre-ischemia, a sing le Pi peak was observed at a chemical shift of 2.5 ppm (pH 7.2). This peak shifted upfield to 1.6 ppm (pH 6.5) and, following reperfusion, r eturned to its pre-ischemia value. During ischemia and for a short tim e following reperfusion, a second, smaller peak was observed which we assigned to a second pool of inorganic phosphate. The data support the proposal by Kraig and coworkers of pH compartmentation between neuron s and glia during and following transient forebrain ischemia.