Activity of Enzymes Involved in Energy Production in the Small Intestine during Suckling-Weaning Transition of Pigs

Abstract

The effect of weaning on a potential metabolic capacity of key enzymes involved in the energy production by porcine enterocytes was investigated. The activity of citrate synthase, isocitrate dehydrogenase, α-ketoglutarate dehydrogenase, glutamate dehydrogenase, alanine aminotransferase and aspartate aminotransferase was determined in the small intestine epithelium of piglets during suckling-weaning transition. Investigations were performed on 5-week-old (suckling), 6-week-old (1st week after weaning) and 7-week-old (2nd week after weaning) piglets. The activity of glutamate dehydrogenase decreased (p < 0.05) during the 1st week after weaning, and remained numerically lower during the 2nd week after weaning than in suckling piglets. The activities of isocitrate dehydrogenase and alanine aminotransferase showed the same pattern as the glutamate dehydrogenase activity and decreased numerically during the 1st and 2nd weeks. The activities of citrate synthase and α-ketoglutarate dehydrogenase were numerically lower in post-weaned piglets (1st and 2nd weeks) than in suckling piglets. In contrast, the activity of aspartate aminotransferase was high and remained unchanged from week 5 to the 2nd week post-weaning. The activities of alanine and aspartate aminotransferase were positively correlated in suckling piglets (r = 0.98, p < 0.05) and at the 1st week after weaning (r = 0.99, p < 0.01). Also, both aminotransferases were positively correlated to the activity of α-ketoglutarate dehydrogenase in suckling piglets (r = 0.95, p < 0.05 and r = 0.95, p < 0.05) and to the activity of isocitrate dehydrogenase during the 1st week after weaning (r = 0.99, p < 0.001 and r = 0.99, p < 0.01). The results indicate additional capacity of the tricarboxylic acid (TCA) cycle for transformation of α-ketoglutarate from other sources than acetyl-CoA such as glutamine, glutamate and other amino acids. Further, the high activity of aspartate aminotransferase also suggests a high capacity of porcine small intestinal epithelium to provide the TCA cycle with oxaloacetate during the suckling-weaning transition.

The profiles of mitochondrial respiration and glycolysis using extracellular flux analysis in porcine enterocyte IPEC-J2

“…Because of limiting feed (energy) intake during the acute phase after weaning, glutamine contributes to alleviate intestinal alterations by providing gut tissue with fuel and precursors for defense systems ( Lallès et al, 2004 ). Madej et al (2002) also showed that the tricarboxylic acid cycle for transformation of a-ketoglutarate was from amino acids (e.g., glutamine, glutamate) than acetyl-CoA in the porcine small intestinal epithelium during suckling–weaning transition.…”

Differential expression of proteins involved in energy production along the crypt-villus axis in early-weaning pig small intestine

“…In addition, epithelial cells in the pig intestine have notably high energy demands due to the rapid renewal of the epithelium (within few days) (2, 36). Previous studies showed the activities of key metabolic enzymes in enterocytes changed during the suckling-weaning transition in pigs (20,21). However, the effect of early weaning on the metabolism of enterocytes along the crypt-villus axis has not yet been elucidated.…”

Glutamine, Glutamate, and Aspartate Improves Morphology and Energy Production of Small Intestine in Piglets with Different Energy Levels Diets

“…The results in the tables were presented as main effects. When no signi cant interaction between treatment and day was found, the differences among treatments or days were evaluated using Tukey HSD test (showed in Table 3,4,5,6). When signi cant interaction between treatment and day was found, a simple main effect analysis would be performed and the differences among 3 treatments across 2 levels of days post-weaning were evaluated using Bonferroni test (showed in Figure 1, 2, 3).…”

“…The intestine of piglet has notably high energy demand due to the repaid renewal of epithelium within few days [4,5]. Hence, the epithelial cells of gastrointestinal (GI) tract require intense anabolic metabolism.…”

“…Undoubtedly, the weaning pigs are not eating enough food and their intestinal mucosa is failing to digest and absorb su cient nutrients to cover their energy requirement for maintenance [3], which are major limitations to improve the growth of piglet after-weaning. Therefore, improving the energy intake from exogenous nutrition is rationally served as a promising approach to protect piglets from weaning stress.The intestine of piglet has notably high energy demand due to the repaid renewal of epithelium within few days [4,5]. Hence, the epithelial cells of gastrointestinal (GI) tract require intense anabolic metabolism.…”