TitleAscorbic acid deficiency decreases the expression of CYP4A1 in liver microsomes of guinea pigs.
Publication TypeJournal Article
Year of Publication1997
AuthorsRoomi MW, Ogg M, Tsao CS, Gibson GG
JournalRes Commun Mol Pathol Pharmacol
Date Published1997 Jan
KeywordsAnimals, Ascorbic Acid, Ascorbic Acid Deficiency, Cytochrome P-450 CYP4A, Cytochrome P-450 Enzyme System, Guinea Pigs, Male, Microsomes, Liver, Mixed Function Oxygenases

The cytochrome P-450 monooxygenase system plays a central role in the oxidation of a wide variety of structurally unrelated compounds. Its contribution is affected by nutritional and several other factors. Ascorbic acid (AA) deficiency decreases the content of cytochrome P-450 in liver microsomes of guinea pigs (GPs). Included in the group of cytochromes P-450 are the phenobarbital and 3-methylcholanthrene inducible moieties. In the present study the effect of AA status on another specific cytochrome P-450, CYP4A1, laurate omega-hydroxylase was investigated. Ascorbic acid may selectively increase or decrease certain forms of cytochromes. For four weeks adult male Hartley GPs were fed a diet containing 2.5 (Group I), 0.1 (Group II) and 0% (Group III) AA. The liver microsomes were isolated at this stage and cytochrome P-450 content was determined. Group III showed a significant decrease in cytochrome P-450 compared to groups I and II. They also showed a marked decrease in aminopyrine N-demethylase activity. The expression of CYP4A1 was evaluated using Western blot and anti-CYP4A1 antibody. Group III GPs showed a marked decrease in CYP4A1 expression. Groups I and II showed similar expression. This study demonstrates that CYP4A1, a specific cytochrome induced by hypolipidemic agents, is decreased by AA deficiency.

Alternate JournalRes. Commun. Mol. Pathol. Pharmacol.
PubMed ID9055344