Fig. 4. Effect of isoflurane on glutamate-induced cell damage. Cultures were exposed to isoflurane during exposure to different concentrations of glutamate. Then culture medium was replaced, terminating exposure to isoflurane and glutamate. Twenty-four hours later, lactate dehydrogenase (LDH) release (nanomoles of lactate converted to pyruvate per minute) in the culture medium was measured. MK-801, 10 μm, was used as a positive control. Values are mean ± SD; n = 12 culture wells per condition. a =P < 0.01 compared with no glutamate, no isoflurane. b =P < 0.01 compared with cultures exposed to equivalent concentrations of glutamate in the absence of isoflurane.