Rapid recovery of rat brain intracellular pH after cardiac arrest and resuscitation

We studied the intracellular pH in rat cerebral cortex of rats subjected to reversible total cerebral ischemia by cardiac arrest and resuscitation. Brain acidosis was more pronounced during ischemia in hyperglycemic rats (6.21 +/- 0.14) than in normoglycemic rats (6.56 +/- 0.07). Brain tissue lactate accumulated proportionally. Nevertheless, within 5 min. of reperfusion, pHi in both normoglycemic and hyperglycemic groups had recovered to baseline levels, i.e. near 7.1-7.2 , despite the fact that lactate concentrations were still elevated. These results demonstrate a rapid reversal of ischemic acidosis during recovery from 10 min. of cardiac arrest. and suggest that acidosis, per se, may not be responsible for neuronal damage following cardiac arrest and resuscitation, even in hyperglycemic conditions.#2216