Oxygen and glucose deprivation-induced neuronal apoptosis is attenuated by halothane and isoflurane

Both in vitro and in vivo evidence supports the reduction of early ischemic, both global and focal, brain injury by volatile anesthetics. However, the protection afforded by volatile anesthetics in later neuronal death, i.e., apoptosis, caused by global ischemia has not been investigated. We induced oxygen and glucose deprivation in neuronal cortical cell cultures prepared from newborn rats on in vitro Days 10-14. This hypoxic (Po-2 < 50 mm Hg) condition was maintained continuously (30, 60, and 90 min). In a separate experiment, the neuronal cell cultures were exposed to isoflurane (1.13%, 2.3%, or 3.3%) or halothane (1.7%,3.4%, or 5.1%) before oxygen and glucose deprivation, with continued exposure to isoflurane or halothane during oxygen and glucose deprivation. After 48 h, neuronal apoptosis was assessed with terminal deoxynucleotidyl transferase-mediated in situ nick-end labeling and DNA gel electrophoresis. Oxygen and glucose deprivation (30, 60, and 90 min) caused significant apoptosis of cerebral cortical cultured neurons. However, pretreatment and continued treatment during the period of oxygen and glucose deprivation with halothane or isoflurane resulted in a concentration-dependent attenuation of oxygen and glucose deprivation-induced neuronal apoptosis.