Effects of volatile anesthetics on hippocampal slice metabolism, response to anoxia with and without glucose.

Anesthetics attenuate ischemic damage and so are often not used when preparing hippocampal slices for studies of ischemic or anoxic damage. In this study, we tested whether halothane, ether or isoflurane, when used briefly during slice preparation, have persistent effects on slice ATP metabolism, protein synthesis or morphology. We also tested the effects of anoxia with and without glucose on these slices. Five minutes of anoxia without glucose (anoxia-aglycemia) caused a dramatic depletion of ATP to less than 22% of control levels, a persistent inhibition of neuronal protein synthesis to less than 10% of control rates and severe morphological damage. Slices prepared using volatile anesthetics showed the same degree of damage due to anoxia-aglycemia, when compared with untreated tissue. In contrast, 5 min anoxia caused a 40% decrease in ATP levels in untreated tissue, but did not damage protein synthesis or morphology. While isoflurane-treated tissue responded identically to anoxia as untreated tissue, both halothane and ether prevented the anoxic ATP fall. These findings suggest that while halothane and ether may have persistent effects on slice responses to anoxia, isoflurane is a good candidate anesthetic for slice preparation procedures.