Interaction between vitamin B6 and source of selenium on the response of the selenium-dependent glutathione peroxidase system to oxidative stress induced by oestrus in pubertal pig

This study aimed to assess the interaction between vitamin B-6 and selenium (Se) for the flow of Se towards the Se-dependent glutathione peroxidase (GPX) system in response to oxidative stress naturally induced by oestrus in a pubertal pig model. At first oestrus, forty-five gilts were randomly assigned to the experimental diets (n=9/group): basal diet (CONT); CONT + 0.3 mg/kg of Na-selenite (MSeB(6)0); MSeB(6)0 + 10 mg/kg of HCI-B-6 (MSeB(6)10); CONT+ 0.3 mg/kg of Se-enriched yeast (OSeB(6)0); and OSeB(6)0 + 10 mg/kg of HCI-B-6 (OSeB(6)10). Blood samples were collected at each oestrus (long-term profiles), and daily from day -4 to +3 (slaughter) of the fourth oestrus (peri-oestrus profiles) after which liver, kidneys, and ovaries were collected. For long-term profiles, CONT had lower blood Se than Se-supplemented gilts (p <0.01) and OSe was higher than MSe (p <0.01). Lower erythrocyte pyridoxa1-5-phosphate was found in B(6)0 than B(6)10 (p <0.01). No treatment effect was observed on GPX activity. For peri-oestrus profiles, treatment effects were similar to long-term profiles. Treatment effects on liver Se were similar to those for long-term blood Se profiles and OSe had higher renal Se concentrations than MSe gilts (p <0.01). Gene expressions of GPX1, GPX3, GPX4, and selenocysteine lyase in liver and kidney were greatest in OSeB(6)10 gilts (p <0.05). These results suggest that dietary B-6 modulate the metabolic pathway of OSe towards the GPX system during the peri-oestrus period in pubertal pigs. Crown Copyright (C) 2015 Published by Elsevier GmbH. All rights reserved.