Efeitos da suplementação de ácido ascórbico durante a realimentação na musculatura de pacus (Piaractus mesopotamicus) submetidos a um período de jejum
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Data
2020-02-27
Autores
Zanella, Bruna Tereza Thomazini [UNESP]
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Universidade Estadual Paulista (Unesp)
Resumo
Períodos de restrição alimentar são comuns em peixes. Nessa condição, ocorre a degradação do tecido muscular e a produção de espécies reativas de oxigênio (ROS), danosas aos seres vivos. Nesse sentido, a adição de antioxidantes como o ácido ascórbico (AA) na alimentação, pode resultar na neutralização e prevenção dos danos ocasionados pelas ROS. O objetivo desse trabalho foi avaliar os impactos da suplementação de AA no músculo esquelético de pacus submetidos ao jejum. Pacus juvenis foram divididos nos grupos: Control (C; alimentação contínua - 200 mg/kg de AA), Fasting (F; 15 dias de jejum) e três grupos realimentados por 30 dias após o jejum: Low (L-AA; 100 mg/kg de AA), Balanced (B-AA; 200 mg/kg de AA) e High supplementation (H-AA; 400 mg/kg de AA). Amostras musculares foram coletadas após jejum (15 dias) e realimentação (6 horas, 15 e 30 dias). Fibras musculares foram mensuradas e separadas em classes de acordo com seu diâmetro; análises bioquímicas foram realizadas para avaliar a atividade de enzimas antioxidantes. A expressão de genes envolvidos nas vias de anabolismo, catabolismo, miogênese e metabolismo oxidativo foram avaliadas por RT-qPCR. Além disso, análises in vitro foram realizadas para comprovar o efeito direto desse protocolo em células musculares. Após o período de jejum, ocorreu a diminuição no diâmetro das fibras e na expressão de genes anabólicos, além de aumento na expressão de genes catabólicos no grupo F. Após um curto período de realimentação (6 horas), houve um aumento na expressão de genes anabólicos e miogênicos no grupo H-AA. Aos 15 dias, observou-se uma diminuição geral na expressão dos genes no grupo L-AA, além de uma recuperação no diâmetro das fibras e aumento na expressão dos genes miogênicos no grupo H-AA. Ao final do período de realimentação, apenas o grupo H-AA apresentou recuperação no diâmetro das maiores fibras, além de aumento na expressão de genes relacionados à miogênese e metabolismo oxidativo. A suplementação de AA promoveu diminuição na atividade da enzima antioxidante catalase ao longo do período experimental nesse mesmo grupo. Nossos dados indicam que a baixa suplementação de AA impactou negativamente na recuperação do metabolismo muscular, enquanto a maior suplementação auxiliou no rápido estabelecimento de condições benéficas ao crescimento, possivelmente, atenuando os efeitos do jejum e mantendo um microambiente favorável à produção energética. Ainda, nossos resultados in vitro indicam um efeito direto do AA em células musculares. Esses resultados podem representar uma estratégia nos sistemas de aquicultura, promovendo uma rápida recuperação muscular após situações de jejum em peixes.
Fasting periods commonly occur throughout the fish’s life. During this condition, there is an increase in muscle degradation and reactive oxygen species (ROS) production, which can cause cell disturbances. Antioxidants, such as ascorbic acid (AA), can neutralize and prevent ROS’s damage. Thus, we aimed to evaluate the AA supplementation impacts in the skeletal muscle of pacu after a fasting period. Pacu juvenile were grouped in Control (C; continuous feeding - 200 mg/kg of AA), Fasting (F; 15 days of fasting) and three refeeding groups after fasting: Low (L-AA; 100 mg/kg of AA), Balanced (B-AA; 200 mg/kg of AA) and High-supplementation (H-AA; 400 mg/kg of AA). Muscle samples were collected after fasting (15 days) and refeeding (6 hours, 15 and 30 days). Muscle fibers were measured and grouped in diameter classes. Biochemistry analyses were performed to evaluate antioxidant enzymes activity. Genes related to anabolism, catabolism, myogenesis and oxidative metabolism were analyzed by RT-qPCR. Besides, in vitro analyzes were performed to evaluate the direct AA effect’s in muscle cells. After fasting, a decrease in fiber diameter and anabolic genes expression, besides an increase in catabolic genes was observed in F group. In the first moment after refeeding (6 hours), the anabolic and myogenic genes expression increased in the H-AA. After 15 days, the L-AA group presented a general decrease in gene expression, while the H-AA had an increase in myogenic genes expression and recovered fiber diameter. After 30 days, the H-AA presented an increase in the expression of genes related to myogenesis and oxidative metabolism combined with a recovery in fiber diameters. Besides, the AA supplementation promoted a decrease in catalase activity through time in this same group. Our data indicate that the low AA level may have impaired muscle metabolism resumption, while the higher supplementation may have contributed to a faster recovery of muscle growth, possibly providing a beneficial microenvironment for energetic production. Moreover, our in vitro results indicate a possible direct AA effect on muscle cells. These findings may present a strategy to minimize the loss of aquaculture profits, promoting faster muscle recovery after fasting and stressful situations.
Fasting periods commonly occur throughout the fish’s life. During this condition, there is an increase in muscle degradation and reactive oxygen species (ROS) production, which can cause cell disturbances. Antioxidants, such as ascorbic acid (AA), can neutralize and prevent ROS’s damage. Thus, we aimed to evaluate the AA supplementation impacts in the skeletal muscle of pacu after a fasting period. Pacu juvenile were grouped in Control (C; continuous feeding - 200 mg/kg of AA), Fasting (F; 15 days of fasting) and three refeeding groups after fasting: Low (L-AA; 100 mg/kg of AA), Balanced (B-AA; 200 mg/kg of AA) and High-supplementation (H-AA; 400 mg/kg of AA). Muscle samples were collected after fasting (15 days) and refeeding (6 hours, 15 and 30 days). Muscle fibers were measured and grouped in diameter classes. Biochemistry analyses were performed to evaluate antioxidant enzymes activity. Genes related to anabolism, catabolism, myogenesis and oxidative metabolism were analyzed by RT-qPCR. Besides, in vitro analyzes were performed to evaluate the direct AA effect’s in muscle cells. After fasting, a decrease in fiber diameter and anabolic genes expression, besides an increase in catabolic genes was observed in F group. In the first moment after refeeding (6 hours), the anabolic and myogenic genes expression increased in the H-AA. After 15 days, the L-AA group presented a general decrease in gene expression, while the H-AA had an increase in myogenic genes expression and recovered fiber diameter. After 30 days, the H-AA presented an increase in the expression of genes related to myogenesis and oxidative metabolism combined with a recovery in fiber diameters. Besides, the AA supplementation promoted a decrease in catalase activity through time in this same group. Our data indicate that the low AA level may have impaired muscle metabolism resumption, while the higher supplementation may have contributed to a faster recovery of muscle growth, possibly providing a beneficial microenvironment for energetic production. Moreover, our in vitro results indicate a possible direct AA effect on muscle cells. These findings may present a strategy to minimize the loss of aquaculture profits, promoting faster muscle recovery after fasting and stressful situations.
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Palavras-chave
Vitamina c, Peixes, Músculo esquelético, Realimentação, Piaractus mesopotamicus