Arginine promotes porcine type I muscle fibers formation through improvement of mitochondrial biogenesis.

This study aimed to investigate whether arginine promotes porcine type I muscle fibers formation via improving mitochondrial biogenesis. In the in vivo study, a total of sixty DLY (Duroc × Landrace × Yorkshire) weaning piglets with an average body weight of 6.55 ± 0.36 kg were randomly divided into four treatments and fed with a basal diet or a basal diet supplemented with 0.5%, 1.0% and 1.5% L-arginine, respectively, in a four-week trial. Results showed that dietary supplementation of 1.0% arginine significantly enhanced the activity of succinate dehydrogenase, upregulated the protein expression of myosin heavy chain I (MyHC I), and increased the mRNA levels of MyHC I, Tnni1, Tnnc1 and Tnnt1 in longissimus dorsi muscle compared with the control group. In addition, ATPase staining analysis indicated that 1.0% arginine supplementation significantly increased the number of type I muscle fibers and significantly decreased the number of type II muscle fibers. Furthermore, 1.0% arginine supplementation significantly upregulated PGC-1α, Sirt1 and Cytc protein expressions, increased PGC-1α, NRF1, TFB1M, Cytc and TP5G mRNA levels and increased mitochondrial DNA content. In the in vitro study, mitochondrial complex I inhibitor rotenone (Rot) was used. We found that Rot annulled Arg-induced type I muscle fibers formation. Together, our results provide for the first time the evidence that Arg promotes porcine type I muscle fibers formation through improvement of mitochondrial bioge...

Source: The British Journal of Nutrition - November 28, 2019 Category: Nutrition Authors: Chen X, Luo X, Chen D, Yu B, He J, Huang Z Tags: Br J Nutr Source Type: research