Ilka Rasch1, Solvig Görs1, Armin Tuchscherer2, Torsten Viergutz3, Cornelia C Metges1,4, Björn Kuhla1. 1. Institute of Nutritional Physiology "Oskar Kellner", Leibniz Institute for Farm Animal Biology (FBN), Dummerstorf, Germany. 2. Institute of Genetics and Biometry, Leibniz Institute for Farm Animal Biology (FBN), Dummerstorf, Germany. 3. Institute of Reproductive Biology, Leibniz Institute for Farm Animal Biology (FBN), Dummerstorf, Germany. 4. Chair of Nutritional Physiology and Animal Nutrition, Faculty of Agriculture and Environmental Sciences, University of Rostock, Rostock, Germany.
Abstract
BACKGROUND: Cys is limiting for reduced glutathione (GSH) synthesis and can be synthesized from Met. We hypothesized that the dietary Met hydroxyl analogue dl-2-hydroxy-4-methylthiobutyric acid (dl-HMTBA) affects Cys and GSH metabolism and oxidative stress defense differently than Met. OBJECTIVE: The objective was to elucidate whether dl-HMTBA supplementation of a Met-deficient diet affects Cys flux, GSH fractional synthetic rate (FSR), and the basal oxidative stress level relative to Met supplementation in pigs. METHODS: Twenty-nine male German Landrace piglets aged 28 d were allocated to 3 dietary groups: a basal diet limiting in Met (69% of Met plus Cys requirement) supplemented with either 0.15% l-Met (LMET; n = 9), 0.15% dl-Met (DLMET; n = 11), or 0.17% dl-HMTBA (DLHMTBA; n = 9) on an equimolar basis. At age 54 d the pigs received a continuous infusion of [1-13C]-Cys to calculate Cys flux and Cys oxidation. After 3 d, GSH FSR was determined by [2,2-2H2]-glycine infusion, and RBC GSH and oxidized GSH concentrations were measured. At age 62 d the animals were killed to determine hepatic mRNA abundances of enzymes involved in GSH metabolism, GSH concentrations, and plasma oxidative stress defense markers. RESULTS: The Cys oxidation was 21-39% and Cys flux 5-15% higher in the fed relative to the feed-deprived state (P < 0.001). On average, GSH FSR was 49% lower (P < 0.01), and RBC GSH and total GSH concentrations were 12% and 9% lower, respectively, in DLHMTBA and DLMET relative to LMET pigs (P < 0.05). In the feed-deprived state, Gly flux, the GSH:oxidized glutathione (GSSG) ratio, RBC GSSG concentrations, plasma oxidative stress markers, and the hepatic GSH content did not differ between groups. CONCLUSIONS: Although GSH FSR was higher in LMET compared with DLMET or DLHMTBA feed-deprived pigs, these differences were not reflected by lower oxidative stress markers and antioxidant defense enzymes in LMET pigs.
BACKGROUND:Cys is limiting for reduced glutathione (GSH) synthesis and can be synthesized from Met. We hypothesized that the dietary Methydroxyl analogue dl-2-hydroxy-4-methylthiobutyric acid (dl-HMTBA) affects Cys and GSH metabolism and oxidative stress defense differently than Met. OBJECTIVE: The objective was to elucidate whether dl-HMTBA supplementation of a Met-deficient diet affects Cys flux, GSH fractional synthetic rate (FSR), and the basal oxidative stress level relative to Met supplementation in pigs. METHODS: Twenty-nine male German Landrace piglets aged 28 d were allocated to 3 dietary groups: a basal diet limiting in Met (69% of Met plus Cys requirement) supplemented with either 0.15% l-Met (LMET; n = 9), 0.15% dl-Met (DLMET; n = 11), or 0.17% dl-HMTBA (DLHMTBA; n = 9) on an equimolar basis. At age 54 d the pigs received a continuous infusion of [1-13C]-Cys to calculate Cys flux and Cys oxidation. After 3 d, GSH FSR was determined by [2,2-2H2]-glycine infusion, and RBC GSH and oxidized GSH concentrations were measured. At age 62 d the animals were killed to determine hepatic mRNA abundances of enzymes involved in GSH metabolism, GSH concentrations, and plasma oxidative stress defense markers. RESULTS: The Cys oxidation was 21-39% and Cys flux 5-15% higher in the fed relative to the feed-deprived state (P < 0.001). On average, GSH FSR was 49% lower (P < 0.01), and RBC GSH and total GSH concentrations were 12% and 9% lower, respectively, in DLHMTBA and DLMET relative to LMETpigs (P < 0.05). In the feed-deprived state, Gly flux, the GSH:oxidized glutathione (GSSG) ratio, RBC GSSG concentrations, plasma oxidative stress markers, and the hepatic GSH content did not differ between groups. CONCLUSIONS: Although GSH FSR was higher in LMET compared with DLMET or DLHMTBA feed-deprived pigs, these differences were not reflected by lower oxidative stress markers and antioxidant defense enzymes in LMETpigs.
Authors: Maaike A Riedijk; Barbara Stoll; Shaji Chacko; Henk Schierbeek; Agneta L Sunehag; Johannes B van Goudoever; Douglas G Burrin Journal: Proc Natl Acad Sci U S A Date: 2007-02-21 Impact factor: 11.205
Authors: Isabel I Schermuly; Stella Romanet; Martina Klünemann; Lucia Mastrototaro; Robert Pieper; Jürgen Zentek; Rose A Whelan; Jörg R Aschenbach Journal: Sci Rep Date: 2022-03-22 Impact factor: 4.996