The effects of aurofusarin in the quail diet on the antioxidant systems of the developing embryo are investigated. Thirty eight 45-day-old Japanese quails (Coturnix japonica) were divided into two groups and were fed on a corn-soya diet or the same diet supplemented with aurofusarin at the level of 26.4 mg/kg feed in the form of Fusarium graminearum culture enriched with aurofusarin. Eggs obtained after 7 weeks of feeding were incubated. Samples of quail tissues were collected at day 17 of embryonic development and from day old hatchlings. Antioxidants and malondialdehyde were analysed by HPLC-based methods. Inclusion of aurofusarin in the maternal diet was associated with decreased concentrations of alpha- and gamma-tocopherols, alpha- and gamma-tocotrienols, retinol, lutein and zeaxanthin in egg yolk. The vitamin E (tocopherols and tocotrienols) concentration in the liver and yolk sac membrane (YSM) of the day 17 embryos and the hatchlings from aurofusarin-fed group was significantly decreased. Alpha-tocopherol concentration was also reduced in kidney, lung, heart, muscle and brain of day-old quails. In the liver of day-old quails, concentrations of lutein, zeaxanthin, retinol, retinyl linoleate, retinyl oleate, retinyl palmitate and retinyl stearate were also reduced. As a result of these diminished antioxidant concentrations, tissue susceptibility to lipid peroxidation was significantly increased. It is suggested that a compromised antioxidant system of the egg yolk and embryonic tissues could predispose quails to increased mortality at late stages of their embryonic development.
Monthly Archives: February 2002
Alpha- and gamma-tocopherol (α- and γ-T, respectively) metabolite analysis is of key relevance in the study of vitamin E metabolism. Whilst there is information on urinary excretion of the two major metabolites of these vitamin E homologues, namely the 2,5,7,8-tetramethyl-2-(β-carboxyethyl)-6-hydroxychroman (α-CEHC) and 2,7,8-trimethyl-2-(β-carboxyethyl)-6-hydroxychroman (γ-CEHC), their concentration and response to supplements in plasma remains poorly investigated. In this study we describe a gas chromatography-mass spectrometry (GC/MS)-based assay to measure both α and γ-T and their corresponding CEHC metabolites in human plasma. As an example of the application of this method we report data obtained following the supplemention of two healthy volunteers with 100 mg of deuterium-labeled _-T acetate (d2-γ-TAC). Under routine analytical conditions a good linearity in the range 0.0025–1µM was observed for both the α- and γ-CEHC deuterated standards. In plasma samples, the detection limit for α- and γ-CEHC was 2.5 and 5 nmol/l, respectively. The minimum amount of plasma required for the assay was 500 µl. The plasma concentrations of α-CEHC and γ-CEHC in unsupplemented healthy subjects were 12.6 ±7.5 and 160.7 ± 44.9 nmol/l, respectively. In the two volunteers supplemented with 100 mg of d2-γ-TAC, plasma d2-γ-T concentrations increased 250 to 450-fold 6 h postsupplementation. Plasma and urinary d2-γ-CEHC concentrations increased 20 to 40-fold 9–12 h postsupplementation. Interestingly, the acute increase in d2 γ-T did not significantly affect the baseline plasma concentrations of d0-γ-T and only slight lowered α-T concentrations. Likewise, plasma α-CEHC levels were not influenced and urinary excretion of α-CEHC were unaltered. This GC/MS method provides a versatile and accurate mean for assessing carboxyethyl-hydroxychroman metabolites of vitamin E in plasma.