Development of an antioxidant system after early weaning in piglets2

Abstract

The objective of this experiment was to investigate oxidative injury and the development of an antioxidant system after early weaning in piglets. A total of 40 piglets (Landrace× Large White, weaned at 14 d after birth) were randomly slaughtered 0 (w0d), 1 (w1d), 3 (w3d), 5 (w5d), or 7 d (w7d; n = 8) after weaning. Concentrations of malondialdehyde (MDA), 8-hydroxydeoxyguanosine (8-OHdG), and protein carbonyl and the activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and catalase were measured in plasma. Gene expressions of antioxidant enzymes were determined by quantitative reverse transcription PCR analysis. The mediation of transcription factor 65 (p65) and the nuclear factor erythroid 2-related factor 2 (Nrf2) signaling pathways by oxidative stress was determined by Western blot analysis. Results showed that the plasma MDA level was significantly higher at 3 d (P < 0.05) and that the protein carbonyl level increased at 1, 3, and 5 d (P < 0.05) compared with w0d. In addition, early weaning suppressed the plasma activity of SOD at 1 d (P < 0.05) and reduced the GSH-Px activity at 3 d (P < 0.05). The expression results in the jejunum indicate that the genes related to antioxidant enzymes were downregulated (P < 0.05) at 3 and 5 d after weaning. Uncoupling protein 2 (Ucp2), which is considered to be a feedback regulation on reactive oxygen species generation, tended to decrease in the ileum (P < 0.05) after weaning. Tumor protein 53 (p53), which regulates reactive oxygen species generation, was enhanced (P < 0.05) in the jejunum after weaning. Meanwhile, early weaning suppressed p65 (at 3, 5, and 7 d; P < 0.05) and Nrf2 (at 5 and 7 d; P < 0.05) signals in the jejunum, which might feedback-regulate antioxidant gene expression and promote the development of the antioxidant system. Therefore, we speculate that weaning disrupted oxidative balance and caused oxidative injury in piglets, and this imbalance can recover with the development of an antioxidant system via feedback regulation.

The effects of iron deficiency on the level of oxidative stress and antioxidant defenses in suckling piglets

“…One week after weaning there was a significant increase in TABRS levels in both groups. This is in line with Zhu et al (2012) and Yin et al (2014) and indicates that weaning was associated with increased oxidative stress.…”

Transient effects of weaning on the health of newly weaning piglets

“…Zhu et al (2012) reported that serum MDA levels increase on day 14 post-weaning, while Yin et al (2014) showed that plasma MDA levels peak on day 3 post-weaning. Additionally, the authors reported that plasma SOD activity decreases on day 1 post-weaning and normalizes on days 3, 5, and 7 post-weaning (Yin et al 2014). Consistent with these results, our study showed that the concentration of serum MDA was the highest on day 4 post-weaning.…”

Fish Oil and Olive Oil Supplementation in Late Pregnancy and Lactation Differentially Affect Oxidative Stress and Inflammation in Sows and Piglets

“…The measurement of GSH-Px activity of plasma and milk was based on the oxidation of NADPH and expressed as U/ml in accordance with the method of Hernández et al [23]. The T-SOD activity was measured by using a procedure reported by Yin et al [24], and the content of α-tocopherol was determined as described by the manufacture' instructions, which were expressed as U/ml and µg/ml for T-SOD activity and the α-tocopherol content, respectively.…”