The effect of ouabain on water diffusion in the rat hippocampal slice measured by high resolution NMR imaging

High resolution NMR imaging of the isolated perfused rat hippocampal slice was used to quantitate ADC changes following ouabain-induced cell swelling. Hippocampal slices were studied in artificial cerebrospinal fluid and then in ouabain using a 600-MHz narrow bore spectrometer and a home-built perfu sion chamber. The brain slices demonstrated biexponential diffusion behavio r. After perfusion with 1 mM ouabain, there was an increase in the fraction of slowly diffusing water. The ADCs of the two fractions did not change. T hese data support the hypothesis that the decrease in the ADC of brain wate r following an ischemic attack is caused by cell swelling. The relative amp litudes of the two diffusing fractions do not match the expected ratio of i ntracellular and extracellular fractions. This discrepancy may be principal ly due to the difference in T-2 relaxation rates of the two compartments. M agn Reson Med 41:137-142, 1999. (C) 1999 Wiley-Liss, Inc.