• protein kinase C;
  • isozymes;
  • human skeletal muscle;
  • skeletal muscle


The immunolocalization of protein kinase C (PKC) isozymes α, βI, and βII, was investigated in human skeletal muscle. All three isozymes were present on the muscle fiber surface membrane and within the muscle fibers. The α-isozyme was most clearly delineated on the surface membrane of the muscle fiber and on small blood vessels in the connective tissue. The axons of myelinated intramuscular nerves stained intensely for the βI isozyme, whereas the endoneurial connective tissue reacted more strongly for the α- and βII-isozymes. PKC isozymes may regulate intracellular signal transduction in human skeletal muscle, as in the other tissues. but their exact role in muscle remains unknown.