The mechanism of action of acetazolamide in the K-deficient diet rat, an animal model of human hypokalemic periodic paralysis (hypoPP), was investigated at the University of Bari, Italy. In vivo administration of acetazolamide prevented paralysis and depolarization of the fibers induced by insulin. Intense sarcolemma Ca-activated K channel activity was recorded in the acetazolamide-treated animals. The serum K levels were also restored to normal by acetazolamide. 
COMMENT. The observed therapeutic effect of acetazolamide in hypokalemic periodic paralysis may be mediated by the activation of the muscular KCa channel.