Original Research ARTICLE
Dietary creatine supplementation in gilthead seabream (Sparus aurata) increases dorsal muscle area and the expression of myod1 and capn1 genes
- 1Centro Interdisciplinar de Investigação Marinha e Ambiental (CIIMAR), Portugal
- 2Abel Salazar Institute of Biomedical Sciences, University of Porto, Portugal
- 3Centro de Ciências do Mar (CCMAR), Portugal
Creatine (Cr) is an amino acid derivative with an important role in the cell as energy buffer, that has been largely used as dietary supplement to increase muscle strength and lean body mass in healthy individuals and athletes. Yet, studies in fish are scarce. The aim of this work was to determine whether dietary Cr supplementation affects muscle growth in gilthead seabream (Sparus aurata) juveniles. Fish were fed ad libitum for 69 days with diets containing three increasing levels of creatine monohydrate (2%, 5% and 8%) that were compared to a non-supplemented control (CTRL) diet. At the end of the trial, the fast-twist skeletal muscle growth dynamics (muscle cellularity) and the expression of muscle-related genes were evaluated. There was a general trend for Cr-fed fish to be larger and longer than those fed the CTRL, but no significant differences in daily growth index (DGI) were registered among dietary treatments. The dorsal cross-sectional muscle area (DMA) of fish fed Cr 5% and Cr 8% was significantly larger than that of fish fed CTRL. The groups supplemented with Cr systematically had a higher relative number of both small-sized (≤20 µm) and large-sized fibres (≥120µm). Dorsal total fibres number was highest in fish fed 5% Cr. In fish supplemented with 5% Cr, the relative expression of myogenic differentiation 1 (myod1) increased almost four times compared to those fed the CTRL diet. The relative expression of calpain 3 (capn3) was highest in fish fed diets with 2% Cr supplementation, but did not differ significantly from those fed the CTRL or Cr 5%. The myod1 gene expression had a positive and significant correlation with that of capn1, capns1a and capn3 expression. These results suggest that the observed modulation of gene expression was not enough to produce a significant alteration in muscle phenotype under the tested conditions, as a non-significant increase in muscle fibre diameter and higher total number of fibre was observed, but still resulted in increased DMA. Additional studies may be required in order to better clarify the effect of dietary Cr supplementation in fish, possibly in conjunction with induced resistance training.
Keywords: Creatine supplementation, Muscle growth and differentiation, myogenesis, Calpains, myogenic differentiation 1 (myod1), Myogenic Regulatory Factors [MRFs]
Received: 12 Jul 2018;
Accepted: 25 Feb 2019.
Edited by:Encarnación Capilla, University of Barcelona, Spain
Reviewed by:Daniel Garcia De La Serrana, University of St Andrews, United Kingdom
Atsushi Asakura, University of Minnesota Twin Cities, United States
Copyright: © 2019 Pinto, Lopes, Sousa, Castro, Schrama, Rodrigues and Valente. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
* Correspondence: Prof. Luisa M. Valente, Centro Interdisciplinar de Investigação Marinha e Ambiental (CIIMAR), Matosinhos, 4450-208, Portugal, email@example.com