Vitamin e decreases the hepatic levels of aldehyde-derived
peroxidation products in rats with iron overload.
Parkkila, Seppo, Onni Niemel[umlaut]a, Robert S. Britton, Kyle E.
Brown, Seppo Yl[umlaut]a-Herttuala, Rosemary O'neill, and Bruce R.
Bacon.
Departments of Anatomy, University of Oulu, and Clinical Chemistry,
University of Helsinki, and AIV Institute, University of Kuopio,
Finland; Division of Gastroenterology and Hepatology, Department of
Internal Medicine, Saint Louis University School of Medicine, St.
Louis, MO 63110
APStracts 2:0187G, 1995.
Hepatic iron overload can cause lipid peroxidation with the formation
of aldehydic products, hepatocellular injury and fibrosis. Vitamin E
([alpha]-tocopherol) may prevent peroxidation-induced hepatic damage.
We used confocal laser scanning microscopy, digital image analysis,
and immunohistochemical methods to quantitate aldehyde-derived
peroxidation products in the liver of rats with experimental iron
overload with and without supplemental vitamin E. A strong
autofluorescent reaction co-localizing with iron deposits was present
in the livers of iron-loaded rats. Fluorescent granules were unevenly
distributed in the cytosol of both hepatocytes and Kupffer cells in
the periportal regions. Immunohistochemical studies revealed the
presence of malondialdehyde adducts in the periportal regions of the
iron-loaded rats. Vitamin E supplementation markedly reduced the
fluorescence intensity and the amount of aldehyde-derived
peroxidation products and changed the distribution of stainable iron
and iron-associated peroxidation products such that their levels were
much decreased in Kupffer cells. These results indicate that
aldehyde-derived covalent chemical addition products are formed in
the liver in iron overload. Vitamin E supplementation markedly
reduces the amount of these compounds and changes their cellular
distribution. These findings should be implicated in the role of
antioxidant therapy in conditions causing iron overload and lipid
peroxidation.
Received 30 May 1995; accepted in final form 31 August 1995.
APS Manuscript Number G232-5.
Article publication pending Am. J. Physiol. (Gastrointest. Liver
Physiology).
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 23 September 1995.