title: Combined effects of dietary arginine, leucine and protein levels on fatty acid composition and gene expression in the muscle and subcutaneous adipose tissue of crossbred pigs.
abstract: The cumulative effects of dietary arginine, leucine and protein levels on fat content, fatty acid composition and mRNA levels of genes controlling lipid metabolism in pig longissimus lumborum muscle and subcutaneous adipose tissue (SAT) were investigated. The experiment was performed on fifty-four intact male pigs (Duroc × Pietrain × Large White × Landrace crossbred), with a live weight ranging from 59 to 92 kg. The pigs were randomly assigned to one of six experimental treatments (n 9). The treatments followed a 2 × 3 factorial arrangement, with two levels of arginine supplementation (0 v. 1 %) and three levels of a basal diet (normal protein diet, NPD; reduced protein diet, RPD; reduced protein diet to achieve 2 % of leucine, RPDL). The results showed that dietary arginine supplementation did not affect the intramuscular fat (IMF) content and back fat thickness, but increased the total fat in SAT. This effect was associated with an increase in fatty acid synthase (FASN) and stearoyl-CoA desaturase (SCD) mRNA levels in SAT, which suggests that arginine might be involved in the differential regulation of some key lipogenic genes in pig muscle and SAT. The increase in IMF content under the RPD, with or without leucine supplementation, was accompanied by increased FASN and SCD mRNA levels. Arginine supplementation did not influence the percentage of main fatty acids, while the RPD had a significant effect on fatty acid composition in both tissues. Leucine supplementation of RPD did not change IMF, total fat of SAT and back fat thickness, but increased 16 : 0 and 18 : 1cis-9 and decreased 18 : 2n-6 in muscle.
authors: CIISA, Faculdade de Medicina Veterinária, Universidade de Lisboa, Avenida da Universidade Técnica, Alto da Ajuda, Lisboa 1300-477, Portugal.
authors: Marta S
authors: MS
authors: Madeira
authors: CIISA, Faculdade de Medicina Veterinária, Universidade de Lisboa, Avenida da Universidade Técnica, Alto da Ajuda, Lisboa 1300-477, Portugal.
authors: Virgínia M R
authors: VM
authors: Pires
authors: CIISA, Faculdade de Medicina Veterinária, Universidade de Lisboa, Avenida da Universidade Técnica, Alto da Ajuda, Lisboa 1300-477, Portugal.
authors: Cristina M
authors: CM
authors: Alfaia
authors: Faculty of Health and Life Sciences, Centre for Research in Biosciences, University of the West of England, Coldharbour Lane, Bristol BS16 1QY, UK.
authors: Richard
authors: R
authors: Luxton
authors: Faculty of Health and Life Sciences, Centre for Research in Biosciences, University of the West of England, Coldharbour Lane, Bristol BS16 1QY, UK.
authors: Olena
authors: O
authors: Doran
authors: CIISA, Faculdade de Medicina Veterinária, Universidade de Lisboa, Avenida da Universidade Técnica, Alto da Ajuda, Lisboa 1300-477, Portugal.
authors: Rui J B
authors: RJ
authors: Bessa
authors: CIISA, Faculdade de Medicina Veterinária, Universidade de Lisboa, Avenida da Universidade Técnica, Alto da Ajuda, Lisboa 1300-477, Portugal.
authors: José A M
authors: JA
authors: Prates
mesh_terms: D050156:Adipogenesis; D050154:Adiposity; D000818:Animals; D001120:Arginine / Q000008:administration & dosage / Q000378:metabolism*; D003433:Crosses, Genetic; D018752:Diet, Fat-Restricted; D018753:Diet, Protein-Restricted / Q000009:adverse effects / Q000662:veterinary*; D054890:Fatty Acid Synthase, Type I / Q000235:genetics / Q000378:metabolism; D005227:Fatty Acids / Q000378:metabolism*; D063427:Food Quality; D018507:Gene Expression Regulation, Developmental; D006801:Humans; D007930:Leucine / Q000008:administration & dosage / Q000378:metabolism*; D050356:Lipid Metabolism; D050155:Lipogenesis; D008297:Male; D008460:Meat / Q000009:adverse effects / Q000032:analysis*; D018482:Muscle, Skeletal / Q000254:growth & development / Q000378:metabolism; D011174:Portugal; D013230:Stearoyl-CoA Desaturase / Q000378:metabolism; D050507:Subcutaneous Fat, Abdominal / Q000254:growth & development / Q000378:metabolism; D034421:Sus scrofa / Q000254:growth & development / Q000378:metabolism*
chemical_list: D005227:Fatty Acids; D001120:Arginine; D013230:Stearoyl-CoA Desaturase; D054890:Fatty Acid Synthase, Type I; D007930:Leucine