Journal Article

The effects of branched-chain amino acid interactions on growth performance, blood metabolites, enzyme kinetics and transcriptomics in weaned pigs

Roth, Franz Xaver, Wiltafsky, Markus Karl, Pfaffl, Michael Walter

2010

Overview

The impact of excess dietary leucine (Leu) was studied in two growth assays with pigs (8–25 kg). In each trial, forty-eight pigs were allotted to one of six dietary groups. The dietary Leu supply increased from treatment L100 to L200 (three increments). To guarantee that interactions between the branched-chain amino acids (BCAA) were not cushioned either surpluses of isoleucine (Ile, expt 1) or valine (Val; expt 2) were avoided. In the fifth treatment, the effects of a simultaneous excess of Leu and Val (expt 1), or of Leu and Ile (expt 2) were investigated. The sixth treatment was a positive control. An increase in dietary Leu decreased growth performance, and increased plasma Leu and serum α-keto-isocaproate levels in a linear, dose-dependent manner. Levels of plasma Ile and Val, and of serum α-keto-β-methylvalerate and α-keto-isovalerate, indicated increased catabolism. Linear increases in the activity of basal branched-chain α-keto acid dehydrogenase in the liver confirmed these findings. No major alterations occurred in the mRNA of branched-chain amino acid catabolism genes. In liver tissue from expt 2, however, the mRNA levels of growth hormone receptor, insulin-like growth factor acid labile subunit and insulin-like growth factor 1 decreased significantly with increasing dietary Leu. In conclusion, excess dietary Leu increased the catabolism of BCAA mainly through posttranscriptional mechanisms. The impact of excess Leu on the growth hormone–insulin-like growth factor-1 axis requires further investigation.

• Publisher: Cambridge University Press
• Subject: 3-methyl-2-oxobutanoate dehydrogenase (lipoamide) / 3-Methyl-2-Oxobutanoate Dehydrogenase (Lipoamide) - metabolism / Amino acid interactions / amino acid metabolism / Amino acids / Amino Acids, Branched-Chain / Amino Acids, Branched-Chain - blood / Amino Acids, Branched-Chain - metabolism / Amino Acids, Branched-Chain - pharmacology / Analysis of Variance / animal growth / animal nutrition / animal performance / Animals / Biological and medical sciences / blood / blood plasma / branched chain amino acids / Branched-chain α-keto acid dehydrogenase / Diet / dose response / Dose-Response Relationship, Drug / drug effects / enzyme activity / enzyme kinetics / Enzymes / Feeding. Feeding behavior / Female / Fundamental and applied biological sciences. Psychology / Gene Expression Profiling / genetics / growth & development / Hogs / hormone receptors / insulin-like growth factor I / isoleucine / Isoleucine - blood / Isoleucine - metabolism / Isoleucine - pharmacology / Keto Acids / Keto Acids - blood / Kinetics / leucine / Leucine - blood / Leucine - metabolism / Leucine - pharmacology / Leucine excess / Linear Models / liver / Liver - metabolism / messenger RNA / Metabolism / Metabolism - drug effects / Metabolism and Metabolic Studies / Metabolites / nutrient excess / nutrient-nutrient interactions / Nutrition research / pharmacology / Pigs / Receptors, Somatotropin / Receptors, Somatotropin - genetics / Receptors, Somatotropin - metabolism / RNA, Messenger / RNA, Messenger - metabolism / Somatomedins / Somatomedins - genetics / Somatomedins - metabolism / Swine / Swine - growth & development / Swine - metabolism / swine feeding / transcriptome / valine / Valine - blood / Valine - metabolism / Valine - pharmacology / Vertebrates: anatomy and physiology, studies on body, several organs or systems / Weaning / young animals