This study aimed to assess the interaction between vitamin B6 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 (MSeB60); MSeB60 + 10 mg/kg of HCl-B6 (MSeB610); CONT + 0.3 mg/kg of Se-enriched yeast (OSeB60); and OSeB60 + 10 mg/kg of HCl-B6 (OSeB610). 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 pyridoxal-5- phosphate was found in B60 than B610 (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 OSeB610 gilts (p < 0.05). These results suggest that dietary B6 modulate the metabolic pathway of OSe towards the GPX system during the peri-oestrus period in pubertal pigs.
Key words: Gilt, Glutathione peroxidase, Oestrus Pyridoxine, Inorganic selenium, Organic selenium.
Abstract published in Journal of Trace Elements in Medicine and Biology 32 (2015) 21–29. http://dx.doi.org/10.1016/j.jtemb.2015.05.002.