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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 HCl-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 HCl-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 pyridoxal-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. [ABSTRACT FROM AUTHOR]

Abstract: The experiment was conducted to compare the effect of different selenium sources on the expression of glutathione peroxidase 1 (GPx1) and iodothyronine deiodinase 1 (Dio1) mRNA in mice by quantitative real-time PCR. A total of 60 male Kunming mice at average body weight of 20g were allotted to three groups in a randomized complete block design, namely two treatments and one control. Mice in Group 1 were fed a basal diet as control, while mice in Groups 2 and 3 were fed the basal diet supplemented with 0.1mg/kg selenium as sodium selenite or selenized yeast, respectively. Whole feeding experiment lasted for 30d. At the end of the feeding trial, liver mRNA levels of GPx1 and Dio1 were determined by quantitative real-time PCR, as well as growth performance, body composition, blood and GPx activity were determined. The results showed that no significant differences in overall growth performance and body composition, including body weight, body length, heart weight, kidney weight and liver weight, were found between the experimental groups (P>0.05). Blood GPx activity increased in all of the selenium supplemented groups compared with control group (P<0.01). However, blood GPx activity in selenized yeast group was higher than that in sodium selenite group (P<0.05). Liver mRNA levels of GPx1 and Dio1 also increased in the two selenium supplemented groups compared with the control group (P<0.05), while there was no significant difference between the sodium selenite and selenized yeast groups (P>0.05). In conclusion, selenium increased the mRNA expression of GPx1 and Dio1 genes in murine liver, and there was no significant difference between the organic or inorganic form of selenium used. [Copyright &y& Elsevier]