P-31 NMR IN-VIVO STUDY OF A RAT-BRAIN PHO SPHATE METABOLIC DISORDER AFTER BILATERAL FOCAL COMPRESSION ISCHEMIA

The dynamics of rat brain energy phosphates and intracellular pH was s tudied during the Ist hour after bilateral focal compression ischemia. The increased inorganic phosphate signal intensity was observed simul taneously with the unchanged pH and phosphocreatine level. Brain energ y status was evaluated by the ATP level and by the Z-index (the averag ed coefficients of correlation between NMR measured brain phosphates i n a given group of animals). Reversible changes of both ATP and Z were observed after 16-28 min of recovery (20% of decrease and 200% of inc rease, respectively). Contrary to ATP the Z-value showed a significant increase in comparison with a corresponding Intact value and with con trol (sham-operated animals). The Z-index is proposed as a sensitive c riteria of brain energy status.