Madeira Marta Sofia Morgado Dos Santos, Rolo Eva Sofia Alves, Pires Virgínia Maria Rico, Alfaia Cristina Maria Riscado Pereira Mateus, Coelho Diogo Francisco Maurício, Lopes Paula Alexandra Antunes Brás, Martins Susana Isabel Vargas, Pinto Rui Manuel Amaro, Prates José António Mestre
CIISA, Faculdade de Medicina Veterinária, Universidade de Lisboa, Avenida da Universidade Técnica, Pólo Universitário do Alto da Ajuda, 1300-477, Lisbon, Portugal.
iMed.UL, Faculdade de Farmácia, Universidade de Lisboa, Avenida Professor Gama Pinto, 1649-003, Lisbon, Portugal.
BMC Vet Res. 2017 May 30;13(1):145. doi: 10.1186/s12917-017-1063-y.
In the present study, the effect of arginine and leucine supplementation, and dietary protein level, were investigated in commercial crossbred pigs to clarify their individual or combined impact on plasma metabolites, hepatic fatty acid composition and mRNA levels of lipid sensitive factors. The experiment was conducted on fifty-four entire male pigs (Duroc × Pietrain × Large White × Landrace crossbred) from 59 to 92 kg of live weight. Each pig was randomly assigned to one of six experimental treatments (n = 9). The treatments followed a 2 × 3 factorial arrangement, providing two levels of arginine supplementation (0 vs. 1%) and three levels of basal diet (normal protein diet, NPD; reduced protein diet, RPD; reduced protein diet with 2% of leucine, RPDL).
Significant interactions between arginine supplementation and protein level were observed across plasma lipids. While dietary arginine increased total lipids, total cholesterol, HDL-cholesterol, LDL-cholesterol, VLDL-cholesterol and triacylglycerols in NPD, the inverse effect was observed in RPD. Overall, dietary treatments had a minor impact on hepatic fatty acid composition. RPD increased 18:1c9 fatty acid while the combination of leucine and RPD reduced 18:0 fatty acid. Arginine supplementation increased the gene expression of FABP1, which contributes for triacylglycerols synthesis without affecting hepatic fatty acids content. RPD, with or without leucine addition, upregulated the lipogenic gene CEBPA but downregulated the fat oxidation gene LPIN1.
Arginine supplementation was responsible for a modulated effect on plasma lipids, which is dependent on dietary protein level. It consistently increased lipaemia in NPD, while reducing the correspondent metabolites in RPD. In contrast, arginine had no major impact, neither on hepatic fatty acids content nor on fatty acid composition. Likewise, leucine supplementation of RPD, regardless the presence of arginine, promoted no changes on total fatty acids in the liver. Ultimately, arginine, leucine and dietary protein reduction seem to be unrelated with fatty liver development.
在本研究中，对商品杂交猪补充精氨酸和亮氨酸以及日粮蛋白质水平的效果进行了研究，以阐明它们对血浆代谢物、肝脏脂肪酸组成和脂质敏感因子mRNA水平的单独或联合影响。实验选用了54头体重59至92千克的雄性猪（杜洛克×皮特兰×大白×长白杂交猪）。每头猪随机分配到六种实验处理之一（n = 9）。处理采用2×3析因设计，提供两种精氨酸补充水平（0%对1%）和三种基础日粮水平（正常蛋白质日粮，NPD；低蛋白日粮，RPD；添加2%亮氨酸的低蛋白日粮，RPDL）。
在血浆脂质方面观察到精氨酸补充和蛋白质水平之间存在显著交互作用。日粮精氨酸在NPD中增加了总脂质、总胆固醇、高密度脂蛋白胆固醇、低密度脂蛋白胆固醇、极低密度脂蛋白胆固醇和三酰甘油，但在RPD中观察到相反的效果。总体而言，日粮处理对肝脏脂肪酸组成影响较小。RPD增加了18:1c9脂肪酸，而亮氨酸与RPD的组合降低了18:0脂肪酸。补充精氨酸增加了FABP1的基因表达，FABP1有助于三酰甘油的合成，且不影响肝脏脂肪酸含量。添加或不添加亮氨酸的RPD上调了生脂基因CEBPA，但下调了脂肪氧化基因LPIN1。
补充精氨酸对血浆脂质有调节作用，这取决于日粮蛋白质水平。它在NPD中持续增加血脂，而在RPD中降低相应的代谢物。相比之下，精氨酸对肝脏脂肪酸含量和脂肪酸组成均无重大影响。同样，无论是否存在精氨酸，在RPD中补充亮氨酸对肝脏总脂肪酸均无变化。最终，精氨酸、亮氨酸和日粮蛋白质减少似乎与脂肪肝的发展无关。
