Subcellular localization of xanthine oxidase in rat hepatocytes: high- resolution immunoelectron microscopic study combined with biochemical analysisM Ichikawa, T Nishino, T Nishino and A Ichikawa Department of Anatomy, School of Medicine, Yokohama City University, Japan. Xanthine oxidase (XO), a molybdo-flavoprotein enzyme involved in purine degradation, was localized immunocytochemically in rat hepatocytes by high-resolution immunoelectron microscopy. XO was isolated from rat liver and a 150 KD polypeptide was purified. Antibodies were raised in rabbits. Small pieces of fresh liver were quickly frozen by contact with a copper block pre-cooled with liquid helium and were freeze- substituted with either 2.5% OsO4 or 0.2% glutaraldehyde in acetone. They were then warmed and embedded in Epon-Araldite or Araldite 6005. Resin sections were treated by indirect immunostaining using anti-rat liver XO antibody and protein A-gold. The labeling pattern was clearly over the cytosol and not on cell organelles. A few gold particles were found over the mitochondrial matrix, but not over the endoplasmic reticulum, Golgi apparatus, lysosomes, or peroxisomes, including their crystalloid core. These results are consistent with those of the biochemical assay of XO in this study. The significance of the occasional immunolabeling of the mitochondrial matrix remains obscure, since biochemical determinations in this study indicate no XO activity in the mitochondrial fraction.
Volume 40,
Issue 8,
pp. 1097-1103,
08/01/1992
|
|||||||||||||||||||||||||||||||||||||||||||||||||
![]() |
C. E. Berry and J. M. Hare Xanthine oxidoreductase and cardiovascular disease: molecular mechanisms and pathophysiological implications J. Physiol., March 15, 2004; 555(3): 589 - 606. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. Stiborova, E. Frei, B. Sopko, K. Sopkova, V. Markova, M. Lankova, T. Kumstyrova, M. Wiessler, and H. H. Schmeiser Human cytosolic enzymes involved in the metabolic activation of carcinogenic aristolochic acid: evidence for reductive activation by human NAD(P)H:quinone oxidoreductase Carcinogenesis, October 1, 2003; 24(10): 1695 - 1703. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. Stiborova, E. Frei, B. Sopko, M. Wiessler, and H. H. Schmeiser Carcinogenic aristolochic acids upon activation by DT-diaphorase form adducts found in DNA of patients with Chinese herbs nephropathy Carcinogenesis, April 1, 2002; 23(4): 617 - 625. [Abstract] [Full Text] [PDF] |
||||
| Guidelines | Subscriptions | About | exPRESS - Current - Archive | Business Information | Contact |