Intracellular localization of the copper-zinc and manganese superoxide dismutases in rat liver parenchymal cells
Slot, J.W.; Geuze, H.J.; Freeman, B.A.; Crapo, J.D.
Laboratory Investigation; a Journal of Technical Methods and Pathology 55(3): 363-371
1986
ISSN/ISBN: 0023-6837 PMID: 3747450 Document Number: 284004
Both the copper-zinc (CuZn) and the manganese (Mn) containing superoxide dismutases (SOD) have been immunolocalized in rat liver sections using protein A-gold labeling on ultrathin cryosections. The CuZnSOD was found to distribute uniformly throughout the nuclear and cytoplasmic matrix. The CuZn enzyme was excluded from membrane-bound compartments such as the nuclear envelope, endoplasmic reticulum, Golgi elements, secretory vesicles, and mitochondria. The primary exception was that lysosomes frequently labeled heavily for CuZnSOD. The lysosomal nature of these membrane-bound bodies was confirmed by double immunolabeling with a lysosomal enzyme, cathepsin-D. The MnSOD was located in mitochondria, particularly the matrix between the cristae. Light but distinct labeling for the MnSOD occurred in the cytoplasmic matrix.