Carbonic anhydrase inhibition and brain electrolyte composition

Abstract

The effects of acetazolamide on cellular electrolyte composition and acid-base status in the brain of rats were compared with the effects of carbon dioxide and diphenylhydantoin. In addition, the effects of acetazolamide on radiosodium turnover in the brain was determined. Acetazolamide decreased intracellular sodium concentration, increased intracellular potassium concentration, and had little effect on intracellular pH. The drug reduced the rate of turnover of radiosodium in the brain. The observations that acetazolamide reduced intracellular sodium concentration and reduced the rate of sodium turnover are interpreted to indicate that the drug decreases the permeability of the neuronal membrane to sodium ion. The reduction in permeability of the neuronal membrane to sodium ion is considered to be a possible mechanism for the anticonvulsant action of this agent.