Muscle Carbonic Anhydrases

In striated muscles, at least three types of carbonic anhydrase (CA) have been demonstrated: (1) a sulfonamide-resistant isozyme, CA III, which appears in the cytosol of red skeletal muscles,7,33,38 (2) a sulfonamide-sensitive cytosolic isozyme, most likely CA II,51 and (3) a membrane-bound form present in the sarcolemma16,23,57 and the sarcoplasmic reticulum (SR).5 Depending on the muscle type, these CA isozymes are variably present at these different sites in the muscle cell.