The isolated, perfused, dog brain preparation was used to investigate the effect of a 10-min period of anoxia and subsequent recovery in 13 separate experimments. The adenylate energy charge, a regulatory parameter with a normal value of 0.90 for brain, decreased to 0.39 during anoxia and recovered to 0.92 within 15 min after oxygen restoration. Glucose uptake and lactate efflux were elevated during the final 3 min of anoxia, but returned to control levels during the recovery period. The concentrations of cerebral metabolites 15 min after restoration of oxygen indicate that phosphofructokinase is impeded, and the activity of hexokinase is reduced, thereby slowing the glycolytic flux to the preanoxic rate. It is concluded that glucose metabolisms is not irreversibly affected by energy charge levels below 0.5 and that other mechanisms may play an equally important role in regulation.
Bibliographical noteFunding Information:
We are indebtedto Dr W. E. Stone for the use of the Spectrofluorometer, A. L. Betz for helpfuld iscussionsa,n dK. Brown,P . Conway,W . Heimana, ndA. Mit-moenf or expertt echnicaal ssistanceT.h is investigationwsa s supportedby Research Grant NS-5961 from the National Instituteo f NeurologicaDl iseasesa nd Stroke and PostdoctoraFle llowshipN IH CA-08068-06fr omthe NationalC ancerI nstitute.