COMPARISON OF IN-VITRO ISCHEMIA-INDUCED DISTURBANCES IN ENERGY-METABOLISM AND PROTEIN-SYNTHESIS IN THE HIPPOCAMPUS OF RATS AND GERBILS

To elucidate whether the high sensitivity of gerbil compared with rat hippocampus to metabolic stress results from tissue-specific or hemody namic factors, ischemia-induced metabolic disturbances [energy metabol ism and protein synthesis rate (PSR)] were studied using the in vitro model of the hippocampal slice preparation. At the end of in vitro isc hemia, ATP content was measured in individual slices with HPLC, in oth er groups of slices, PSR was measured after 120 min of recovery after in vitro ischemia, ATP breakdown was almost identical in rat and gerbi l slices at all temperatures (37 degrees C, 34 degrees C, or 31 degree s C) and periods of ischemia (5, 10, or 15 min) studied. In contrast t o the identical rate of ATP depletion during ischemia, however, postis chemic disturbances in PSR were significantly increased in gerbil slic es compared with rat slices and this relationship was stable after dif ferent periods of ischemia and at different incubation temperatures. T he results illustrate that the pattern of ischemia-induced disturbance s observed in vivo can also be reproduced using the in vitro model of hippocampal slice preparation, as evidenced by the postischemic distur bance in PSR, It is concluded that comparison of the extent of metabol ic disturbances in gerbil and rat hippocampal slices after transient i n vitro ischemia may help to elucidate the mechanisms of ischemic cell damage.