Immunohistochemical localization of creatine phosphokinase in skeletal muscle.

A specific antiserum against skeletal muscle creatine phosphokinase has been obtained by immunizing chickens with purified rabbit skeletal muscle creatine phosphokinase. The antiserum was organ- rather than species-specific and reacted equally well with creatine phosphokinase from rabbit, guinea pig, and human skeletal muscle. Immunological specificity was verified by double immunodiffusion in agar gel where the precipitin line exhibited creatine phosphokinase activity. In solution the antiserum inhibited the enzymatic activity of creatine phosphokinase. By means of the immunofluorescent technique, creatine phosphokinase was localized in the intermyofibrillar space of normal human skeletal muscle fibers in cryostat sections. A higher concentration of the enzyme was found in fibers which have primarily an anaerobic enzyme profile (type II fibers) as determined by conventional histochemical reactions.