Relationship between blood, liver and brain pyridoxal phosphate and pyridoxamine phosphate concentrations in mice.

Plasma pyridoxal 5'-phosphate (PLP) concentrations are considered to be the most reliable single indicator of vitamin B-6 nutritional status and are thought to reflect tissue PLP and pyridoxamine 5'-phosphate (PMP) levels. We investigated the relationship between dietary level of pyridoxine hydrochloride (PN-HCl) and concentrations of PLP in blood and PLP and PMP in liver and brain of mice. Female heterogeneous stock mice, 60 to 90 d old, were fed purified diets containing 0.

Vitamin B-6 metabolic enzymes in blood and placenta of pregnant mice.

Plasma pyridoxal 5'-phosphate (PLP) concentrations decrease 50% in pregnant mice and erythrocyte PLP levels increase threefold over nonpregnant levels. These studies were designed to determine whether changes in the enzymes involved in synthesis and degradation of PLP in blood are altered during pregnancy. We measured net synthesis of PLP in erythrocytes and the activity of enzymes involved in the regulation of plasma and erythrocyte PLP concentration: erythrocyte pyridoxal kinase (PLK) and neutral phosphatase, and plasma and tissue alkaline phosphatase (ALP).

Pyridoxal 5'-phosphate and pyridoxamine 5'-phosphate concentrations in blood and tissues of mice fed ethanol-containing liquid diets.

The effects of chronic ethanol administration on vitamin B-6 metabolism were studied in female Long-Sleep (LS) and Short-Sleep (SS) mice. Animals were fed an ethanol containing liquid diet (AIN-76) for four weeks. Concentration of ethanol in the diet increased from 10 to 25% ethanol-derived calories (EDC) during weeks 1-3 and was maintained at 30% EDC for 1 additional week.

Changes in pyridoxal phosphate and pyridoxamine phosphate in blood, liver and brain in the pregnant mouse.

A decrease in plasma pyridoxal-5'-phosphate (PLP) occurs during pregnancy in humans and experimental animals for reasons that are not known. To determine if mice also develop decreased plasma PLP concentrations during pregnancy, and if plasma PLP levels in pregnancy reflect tissue levels of PLP and pyridoxamine-5'-phosphate (PMP), we measured PLP concentrations in plasma, erythrocytes and whole blood, and liver and brain PLP and PMP in control and pregnant mice. Mice were fed a nonpurified diet containing 8.

Regulation of xanthine oxidase activity and immunologically detectable protein in rats in response to dietary protein and iron.

To investigate the mechanism for changes in xanthine oxidase activity in response to dietary protein and iron, we fed rats diets containing 50, 20 or 5% casein with either normal iron (35 mg Fe/kg diet) or low iron (5 mg Fe/kg diet). Xanthine oxidase activity changed in liver and intestinal mucosa in response to protein and iron, but immunologically detectable xanthine oxidase protein did not change. When total liver RNA isolated from these rats was translated by a rabbit reticulocyte lysate, we found no difference in the amount of xanthine oxidase that was translated.