Comparison of In Vitro Ischemia‐Induced Disturbances in Energy Metabolism and Protein Synthesis in the Hippocampus of Rats and Gerbils

Abstract

To elucidate whether the high sensitivity of gerbil compared with rat hippocampus to metabolic stress results from tissue‐specific or hemodynamic factors, ischemia‐induced metabolic disturbances [energy metabolism and protein synthesis rate (PSR)] were studied using the in vitro model of the hippocampal slice preparation. At the end of in vitro ischemia, ATP content was measured in individual slices with HPLC. In other groups of slices, PSR was measured after 120 min of recovery after in vitro ischemia. ATP breakdown was almost identical in rat and gerbil slices at all temperatures (37°C, 34°C, or 31°C) and periods of ischemia (5, 10, or 15 min) studied. In contrast to the identical rate of ATP depletion during ischemia, however, postischemic disturbances in PSR were significantly increased in gerbil slices compared with rat slices and this relationship was stable after different periods of ischemia and at different incubation temperatures. The results illustrate that the pattern of ischemia‐induced disturbances observed in vivo can also be reproduced using the in vitro model of hippocampal slice preparation, as evidenced by the postischemic disturbance in PSR. It is concluded that comparison of the extent of metabolic disturbances in gerbil and rat hippocampal slices after transient in vitro ischemia may help to elucidate the mechanisms of ischemic cell damage.

Intracellular ATP Influences Synaptic Plasticity in Area CA1 of Rat Hippocampus via Metabolism to Adenosine and Activity-Dependent Activation of Adenosine A1Receptors

“…As seen in this and many other reports (McIlwain, 1952;Thomas, 1957;Kass and Lipton, 1982;Fredholm et al, 1984;Whittingham et al, 1989;Paschen and Djuricic, 1995;Milusheva et al, 1996), brain slices have ϳ40 -60% lower ATP and TAN levels than the in vivo brain (Supplemental References). Our results suggest that this is attributable to the loss of adenine nucleotides and/or their metabolites, especially in hippocampal tissue, during slice preparation.…”

Depletion of Neuronal Endoplasmic Reticulum Calcium Stores by Thapsigargin: Effect on Protein Synthesis

“…CSF (aCSF), prechilled to 4°C.The aCSF was composed of 111 mM NaCl, 26 mM NaHCO 3, 3 mM KC1, 1.4 mM KH2PO4, 1.2 mM CaC12, 1.3 mM MgSO4, 10 mM glucose, and 5.0 mM HEPES. In addition, aCSF was supplemented with individual amino acids as described recently (Paschen and Djuricic, 1995): 34 ,aM alanine, 22~iMarginine, 0.13 ,iM aspartate, 5.7 p~Mcitrulline, 0.12~uMcystine, 13 jiM histidine, 27.7 jiM lysine, 3.4 jiM methionine, 3.8 jiM ornithine, 9.1 jiM phenylalanine, 28.5 jiM serine, 8 jiM taurine, 32 jiM threonine, 1.5 jiM tryptophan, 8.3 jiM tyrosine, and 12.8 1aM valine. aCSF was equilibrated with a gas mixture of 95% 02 and 5% CO2 for at least 60 mm, and the pH of the medium was checked and adjusted, if necessary, to 7.4 with NaOH or HC1 before starting the experiments.…”

“…In one subset of experiments the levels of ATP, ADP, and AMP were determined (together with the adenylate en- (Paschen and Djuricic, 1995). Quantification was carried out using external standard solutions.…”

Early induction of secretoneurin expression following kainic acid administration at convulsant doses in the rat and gerbil hippocampus

“…For instance, the calcium-binding protein parvalbumin is more strongly expressed in the perforant path from the entorhinal cortex to the hippocampus in the gerbil when compared to the rat (Nitsch et al, 1995). On the other hand, the gerbil is more sensitive than the rat to ischemia-induced depolarization and metabolic stress (Stittsworth and Lanthorn, 1994a;Paschen and Djuricic, 1995). In addition, resistance to epileptic, but not anoxic, depolarization has been shown in slice gerbil preparations (Stittsworth and Lanthorn, 1994b).…”