RAPID RECOVERY OF RAT-BRAIN INTRACELLULAR PH AFTER CARDIAC-ARREST ANDRESUSCITATION

We studied the intracellular pH in rat cerebral cortex of rats subject ed to reversible total cerebral ischemia by cardiac arrest and resusci tation. Brain acidosis was more pronounced during ischemia in hypergly cemic rats (6.21 +/- 0.14) than in normoglycemic rats (6.56 +/- 0.07). Brain tissue lactate accumulated proportionally. Nevertheless, within 5 min of reperfusion, pH(i) in both normoglycemic and hyperglycemic g roups had recovered to baseline levels, i.e. near 7.1-7.2, despite the fact that lactate concentrations were still elevated. These results d emonstrate a rapid reversal of ischemic acidosis during recovery from 10 min of cardiac arrest. and suggest that acidosis, per se, may not b e responsible for neuronal damage following cardiac arrest and resusci tation, even in hyperglycemic conditions.