Electroporation (also termed electropermeabilization) of muscle tissue has been studied in several contexts. It has been shown that electroporation plays an important role in muscle damage as a result of electrical injury (1 ,2 ) and that electroporation of cardiac muscle occurs during defibrillation or cardioversion (3 ,4 ). As electroporation has been shown to greatly enhance the cytotoxic effect of certain chemotherapeutic agents, and as clinical Phase I-II studies (5 –8 ) have shown that the combination of electroporation and chemotherapy (electrochemotherapy) is highly efficient against various localized cancers, the question of normal tissue sensitivity to electroporation needs to be investigated. Finally, efficient in vivo gene transfection to muscle tissue by electroporation has recently been reported (9 ,10 ), warranting increased knowledge on in vivo electroporation of muscle tissue.
