Dietary magnesium depletion: p-nitroanisole metabolism and glucuronidation in rat hepatocytes and hepatic microsomal membranes.
Male Sprague-Dawley rats were pair fed either a control magnesium diet (480 mg/kg) or a magnesium-deficient diet (30 mg/kg) for 10 days to produce magnesium depletion. Serum magnesium concentration declined 60%, but tissue magnesium deficiency was not apparent. Hepatic parenchymal cells and microsomal membranes were isolated to evaluate in vitro metabolism of p-nitroanisole and conjugation of its metabolite, p-nitrophenol (pNP). O-Demethylation of p-nitroanisole was decreased slightly in both magnesium depletion hepatocytes and microsomal membranes. However, pNP glucuronide formation was specifically decreased 50% in the magnesium depletion cells at all p-nitroanisole concentrations. Similar results were found in the microsomal reaction system measuring pNP conjugation. Thus, early stages of magnesium depletion may result in a specific decrease in the pNP UDP-glucuronyl transferase activity.
Brown
R C
RC
Department of Pharmacology and Nutrition, University of Southern California School of Medicine, Los Angeles 90033.
Bidlack
W R
WR
D000818:Animals; D000840:Anisoles / Q000378:metabolism*; D004032:Diet; D005965:Glucuronates / Q000378:metabolism; D014453:Glucuronosyltransferase / Q000378:metabolism; D007425:Intracellular Membranes / Q000187:drug effects / Q000378:metabolism*; D007700:Kinetics; D008099:Liver / Q000187:drug effects / Q000378:metabolism*; D008274:Magnesium / Q000494:pharmacology*; D008275:Magnesium Deficiency / Q000378:metabolism*; D008297:Male; D008862:Microsomes, Liver / Q000187:drug effects / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D012016:Reference Values
D000840:Anisoles; D005965:Glucuronates; D014453:Glucuronosyltransferase; C005306:4-nitroanisole; D008274:Magnesium