Changes of ATP and ADP in cultured astrocytes under and after in vitro ischemia

A very large body of evidence from in vivo studies has been accumulated on a link between the change of energy and cell survival/apoptosis. Using an in vitro ischemia model, we have previously shown that ischemia could induce apoptosis in astrocytes. In this study, we utilized the same in vitro model to investigate changes in ATP and ADP levels in cultured astrocytes and attempted to demonstrate an energy-cell death linkage. Astrocytes remained unaltered after 2 hr of ischemia but were moderately or severely damaged after 4 or 6-8 hr, respectively. The astrocytes that survived various lengths of in vitro ischemic incubation retained their ability to produce ATP after ischemia. Both ATP and ADP levels were increased in astrocytes that remained alive under in vitro ischemia for over 6 hr. The largest decline in the percent of viable astrocytes during ischemia corresponded well to the reduction in ATP and ADP levels in these cultures.