Constanza Rivera

L‐arginine induces the expression of utrophin in skeletal muscle cells, so it has been proposed as a pharmacological treatment to attenuate the symptoms of Duchenne muscular dystrophy (DMD). On the other hand, it has been described that one of the pathways that participates in the expression of utrophin in muscle is the Neuregulin‐1 (NRG‐1)/ErbB receptors pathway. Several studies have postulated that disintegrin and metalloprotease‐17 (ADAM17) causes the proteolytic processing of NRG of transmembrane, allowing the release of NRG to the medium, which when joining its ErbB receptor activates the signaling pathway that triggers utrophin transcription. The aim of this study was to evaluate the effect of L‐arginine in the activation of NRG‐1/ErbB pathway and utrophin mRNA levels in C2C12 cells, and the participation of ADAM17 in this process. Our results indicate that L‐arginine induces phosphorylation of ErbB2 and increases utrophin mRNA levels in C2C12 myotubes, with a maximum increase of 2‐fold at 4 h post‐stimulation. This effect is not observed when the myotubes are stimulated in the presence of GM6001 (general metalloprotease inhibitor) or PD‐158780 (specific inhibitor of ErbB receptor phosphorylation). Experiments performed by flow cytometry suggest that L‐arginine stimulates ADAM17 activation in our study model. Furthermore, immunofluorescence analysis supports our findings that L‐arginine stimulates ADAM17 increase in treated myotubes. However, our results using pharmacological inhibitors suggest that ADAM17 does not participate in utrophin expression in C2C12 cells treated with L‐arginine. The results obtained help to clarify the mechanism of action of L‐arginine in the expression of utrophin in muscle cells, which will contribute to the design of new therapeutic strategies in pathologies such as DMD.

Flavor is a determining attribute in the choice of foods and culinary preparations. Taste and preferences for different flavors have been little explored in the Chilean population. The aim of this exploratory study was to determine the liking opinion and preferences for primary flavors and their combinations, aromatic flavors and ethnic flavors in 149 university students. The most liked flavors were salty (91.2%), sweet (89.5%), fruity (83.8%) and Chinese (80.0%) with some differences according to sex. On the contrary, the least liked flavors were bitter and its combinations, spicy (39.9%) and Indian (8.32%), without differences between sex We hope that this information will contribute to improve the current understanding about the acceptability for new gastronomic trends derived from increased migratory phenomenon in Chile, to increase culinary diversity of the national diet.