Effects of vitamin A deficiency on selected xenobiotic-metabolizing enzymes and defenses against oxidative stress in mouse liver.

Abstract

Male and female C57B1/6 mice were rendered vitamin A-deficient, and the effects of this deficiency on certain xenobiotic-metabolizing enzymes and defenses against oxidative stress were examined. Vitamin A deficiency significantly increased the levels of DT-diaphorase, glutathione transferase, and catalase in the hepatic cytosolic fraction from male mice (5.2-, 1.6-, and 3.5-fold, respectively), as well as from female mice (4.8-, 3.3-, and 2.4-fold, respectively). In the hepatic mitochondrial fraction (containing peroxisomes) from male animals, the activities of urate oxidase and catalase were increased 3.4- and 1.7-fold, respectively. The activity of catalase in the mitochondrial fraction from female mice was not affected by vitamin A deficiency, whereas the activity of peroxisomal urate oxidase was increased 2.9-fold. The hepatic level of ubiquinone was increased somewhat. The significance of the increases observed here is presently unclear, but it may be speculated that vitamin A and/or its metabolites are somehow involved in the down-regulation of these proteins. Another possibility is that these enzymes are increased as a result of hepatic oxidative stress caused by vitamin A deficiency. However, vitamin A deficiency had no effect on the activity of superoxide dismutase in this study, whereas the activity of glutathione peroxidase was slightly decreased (27%) in the hepatic cytosolic fraction from male mice. In addition, the hepatic level of alpha-tocopherol was decreased dramatically in the vitamin A-deficient animals.

• Authors: A K Sohlenius-Sternbeck, E L Appelkvist, J W DePierre
• Journal: Biochemical pharmacology (Biochem Pharmacol) Vol. 59 Issue 4 Pg. 377-83 (Feb 15 2000) ISSN: 0006-2952 [Print] England
• PMID: 10644045 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Antioxidants
• Xenobiotics
• Ubiquinone
• Vitamin E

Topics

• Animals
• Antioxidants (metabolism)
• Female
• Liver (enzymology, metabolism)
• Male
• Mice
• Mice, Inbred C57BL
• Organ Size
• Oxidative Stress (physiology)
• Sex Characteristics
• Ubiquinone (metabolism)
• Vitamin A Deficiency (enzymology, physiopathology)
• Vitamin E (metabolism)
• Xenobiotics (metabolism)