Amanda Christine da Silva Sponton

Creatine supplementation and oxidative stress in rat liver

BackgroundThe objective of this study was to determine the effects of creatine supplementation on liver biomarkers of oxidative stress in exercise-trained rats.MethodsForty 90-day-old adult male Wistar rats were assigned to four groups for the eight-week experiment. Control group (C) rats received a balanced control diet; creatine control group (CCr) rats received a balanced diet supplemented with 2% creatine; trained group (T) rats received a balanced diet and intense exercise training equivalent to the maximal lactate steady state phase; and supplemented-trained (TCr) rats were given a balanced diet supplemented with 2% creatine and subjected to intense exercise training equivalent to the maximal lactate steady state phase. At the end of the experimental period, concentrations of creatine, hydrogen peroxide (H2O2) and thiobarbituric acid reactive substances (TBARS) were measured as well as the enzyme activity of superoxide dismutase (SOD), glutathione peroxidase (GSH-GPx) and catalase (CAT). Liver tissue levels of reduced glutathione (GSH), oxidized glutathione (GSSG) and the GSH/GSSG ratio were also determined.ResultsHepatic creatine levels were highest in the CCr and TCr groups with increased concentration of H2O2 observed in the T and TCr animal groups. SOD activity was decreased in the TCr group. GSH-GPx activity was increased in the T and TCr groups while CAT was elevated in the CCr and TCr groups. GSH, GGS and the GSH/GSSG ratio did not differ between all animal subsets.ConclusionsOur results demonstrate that creatine supplementation acts in an additive manner to physical training to raise antioxidant enzymes in rat liver. However, because markers of liver oxidative stress were unchanged, this finding may also indicate that training-induced oxidative stress cannot be ameliorated by creatine supplementation.

Moderate physical activity from childhood contributes to metabolic health and reduces hepatic fat accumulation in adult rats

BackgroundObesity, oxidative stress and inflammation, by triggering insulin resistance, may contribute to the accumulation of hepatic fat, and this accumulation by lipotoxicity can lead the organ to fail. Because obesity is growing at an alarming rate and, worryingly, in a precocious way, the present study aimed to investigate the effects of moderate physical training performed from childhood to adulthood on liver fat metabolism in rats.MethodsTwenty rats that were 28 days old were divided into two groups: control (C) and trained (T). The C Group was kept in cages without exercise, and the T group was submitted to swimming exercise for 1 hour/day, 5 days/week from 28 to 90 days of age (8 weeks) at 80% of the anaerobic threshold determined by the lactate minimum test. At the end of the experiment, the body weight gain, insulin sensitivity (glucose disappearance rate during the insulin tolerance test), concentrations of free fatty acids (FFA) and triglycerides (TG) and hepatic lipogenic rate were analyzed. For the statistical analysis, the Student t-test was used with the level of significance preset at 5%.ResultsThe T group showed lower body weight gain, FFA concentrations, fat accumulation, hepatic lipogenic rate and insulin resistance.ConclusionThe regular practice of moderate physical exercise from childhood can contribute to the reduction of obesity and insulin resistance and help prevent the development of accumulation of hepatic fat in adulthood.

Alterações bioquímicas e hepáticas em ratos submetidos à uma dieta hiperlipídica/hiperenergética

Universidade Estadual Paulista Julio de Mesquita Filho Instituto de Biociencias Departamento de Educacao Fisica

Effects of physical training with different intensities of effort on lipid metabolism in rats submitted to the neonatal application of alloxan

BackgroundType 2 diabetes mellitus (T2DM) is a chronic disease that is characterized by insulin resistance. Its development is directly connected with the inability of insulin to exert its action, not just on carbohydrate metabolism but also on primarily on lipid metabolism. The present study aimed to compare the effects of continuous, intermittent, and strength training on serum and tissue variables on the lipid metabolism of alloxan rats.MethodsWistar rats were divided into eight groups: sedentary alloxan (SA), sedentary control (SC), continuous training alloxan (CA), intermittent training alloxan (IA), strength training alloxan (StA), continuous training control (CC), intermittent training control (IC) and strength training control (StC). Alloxan (250 mg/kg bw) was injected into neonatal rats at 6 days of age. The continuous training protocol consisted of 12 weeks of swimming training for 1 uninterrupted hour / day, five days/ week, supporting a load that was 5% bw. The intermittent training protocol consisted of 12 weeks of swimming training with 30 s of activity interrupted by 30 s of rest, for a total of 20 min/day, five days/ week, supporting a load that was 15% bw. The strength-training protocol consisted of 12 weeks of training, five days/week with 4 sets of 10 jumps in water with 1 min rest between sets, supporting a load that was a 50% bw.ResultsAt 28 days, the alloxan animals exhibited higher insulin resistance as measured by the disappearance of glucose serum (% Kitt/min) during the ITT. At 120 days, the sedentary alloxan animals showed higher FFA values than continuous and intermittent training alloxan. In addition, the alloxan animals that underwent intermittent and strength training showed lower FFA values compared to the corresponding controls. The continuous training protocol was less effective than the strength training protocol for reducing the levels of total cholesterol in the alloxan animals. Serum total lipid values revealed that intermittent training increased serum levels in alloxan animalsConclusionThus, it was concluded that physical training at different intensities of effort is of great importance in attenuation and control of changes in the lipid metabolism in alloxan animals.

Influence of creatine supplementation on indicators of glucose metabolism in skeletal muscle of exercised rats

El objetivo de este estudio fue evaluar el efecto de la suplementacion con creatina en la dieta sobre indicadores del metabolismo de glucosa en el musculo esqueletico en ratones ejercitados. Cuarenta ratas macho adultas Wistar se dividieron en cuatro grupos de ocho semanas: Control: recibieron dieta equilibrada, mantenido sedentaria; Control Complementado: La suplementacion con creatina recibido (2%) en la dieta equilibrada, sedentaria mantenido; Trained: corriendo en una cinta en la intensidad de maximo estado estable de lactato y recibio el grupo de dieta equilibrada y grupo Treinado Complementado: corriendo sobre una cinta rodante a una intensidad maxima de lactato estable y recibieron la suplementacion con creatina (2%) en una dieta equilibrada. El consumo de agua aumenta y reduccion de la ganancia de peso corporal en la formacion y complementado. En el musculo soleo, la oxidacion de la glucosa aumento en ambos grupos suplementados. La produccion de los niveles de lactato y de glucosa durante la prueba de tolerancia a la glucosa disminuida en la formacion y complementado. La suplementacion con creatina en conjunto con el entrenamiento fisico mejora el metabolismo de la glucosa en el musculo de los ratones.O objetivo deste estudo foi avaliar o efeito da suplementacao de creatina na dieta sobre indicadores do metabolismo glicidico musculoesqueletico de ratos exercitados. Quarenta ratos Wistar adultos foram divididos em quatro grupos por oito semanas: Controle: receberam dieta balanceada, mantidos sedentarios; Controle Creatina: receberam suplementacao de creatina (2%) na dieta balanceada, mantidos sedentarios; Treinado: correram em esteira na intensidade da maxima fase estavel de lactato e receberam a dieta balanceada e grupo Treinado Suplementado: correram em esteira na intensidade da maxima fase estavel de lactato e receberam suplementacao de creatina (2%) na dieta balanceada. A ingestao hidrica aumentou e o ganho de massa corporal reduziu no grupo treinado e suplementado. No musculo soleo, a oxidacao de glicose aumentou em ambos os grupos suplementados. A producao de lactato e a glicemia durante teste de tolerância a glicose diminuiram no grupo treinado e suplementado. A suplementacao com creatina em conjunto com treinamento fisico melhorou metabolismo de glicidico muscular dos ratos.

Circulating Concentrations of Adipocytokines and Their Receptors in the Isolated Corpus Cavernosum and Femoral Artery from Trained Rats on a High-Fat Diet

Background: The aim of the present study was to evaluate different signaling pathways by which exercise training would interfere in endothelial function in obesity. Therefore, we examined adipocytokine levels and their receptors in the corpus cavernosum and femoral artery from trained rats on a high-fat diet. Methods: Functional experiments were performed in control sedentary and trained rats, and sedentary (h-SD) and trained male Wistar rats on a high-fat diet (h-TR). Nitric oxide (NO) and reactive oxygen species (ROS) were evaluated in vascular tissue. Circulating adipocytokines and their receptors were analyzed. Results: In the h-SD group, the maximal responses to acetylcholine (ACh) were reduced in the femoral artery and corpus cavernosum as well as the electrical field stimulation, accompanied by an increase in circulating insulin, leptin, TNF-α, MCP-1, and PAI-1. Downregulation of ObR protein expression in the femoral artery was observed without alterations in AdipoR1 and TNFR1 in both preparations. A positive effect was observed in the h-TR group regarding the relaxation response to ACh and circulating adipocytokines, resulting in increased NO production and reduced ROS generation. Exercise restored the ObR protein expression only in the femoral artery. Conclusion: Aerobic exercise training ameliorated the inflammatory adipocytokines and restored the relaxation responses in the corpus cavernosum and femoral artery in rats on a high-fat diet.

Influência da suplementação com creatina em indicadores de metabolismo da glucose no músculo esquelético de ratos exercitados

El objetivo de este estudio fue evaluar el efecto de la suplementacion con creatina en la dieta sobre indicadores del metabolismo de glucosa en el musculo esqueletico en ratones ejercitados. Cuarenta ratas macho adultas Wistar se dividieron en cuatro grupos de ocho semanas: Control: recibieron dieta equilibrada, mantenido sedentaria; Control Complementado: La suplementacion con creatina recibido (2%) en la dieta equilibrada, sedentaria mantenido; Trained: corriendo en una cinta en la intensidad de maximo estado estable de lactato y recibio el grupo de dieta equilibrada y grupo Treinado Complementado: corriendo sobre una cinta rodante a una intensidad maxima de lactato estable y recibieron la suplementacion con creatina (2%) en una dieta equilibrada. El consumo de agua aumenta y reduccion de la ganancia de peso corporal en la formacion y complementado. En el musculo soleo, la oxidacion de la glucosa aumento en ambos grupos suplementados. La produccion de los niveles de lactato y de glucosa durante la prueba de tolerancia a la glucosa disminuida en la formacion y complementado. La suplementacion con creatina en conjunto con el entrenamiento fisico mejora el metabolismo de la glucosa en el musculo de los ratones.O objetivo deste estudo foi avaliar o efeito da suplementacao de creatina na dieta sobre indicadores do metabolismo glicidico musculoesqueletico de ratos exercitados. Quarenta ratos Wistar adultos foram divididos em quatro grupos por oito semanas: Controle: receberam dieta balanceada, mantidos sedentarios; Controle Creatina: receberam suplementacao de creatina (2%) na dieta balanceada, mantidos sedentarios; Treinado: correram em esteira na intensidade da maxima fase estavel de lactato e receberam a dieta balanceada e grupo Treinado Suplementado: correram em esteira na intensidade da maxima fase estavel de lactato e receberam suplementacao de creatina (2%) na dieta balanceada. A ingestao hidrica aumentou e o ganho de massa corporal reduziu no grupo treinado e suplementado. No musculo soleo, a oxidacao de glicose aumentou em ambos os grupos suplementados. A producao de lactato e a glicemia durante teste de tolerância a glicose diminuiram no grupo treinado e suplementado. A suplementacao com creatina em conjunto com treinamento fisico melhorou metabolismo de glicidico muscular dos ratos.

Influencia de la suplementación con creatina sobre indicadores del metabolismo de la glucosa en el músculo esquelético de ratas ejercitadas

El objetivo de este estudio fue evaluar el efecto de la suplementacion con creatina en la dieta sobre indicadores del metabolismo de glucosa en el musculo esqueletico en ratones ejercitados. Cuarenta ratas macho adultas Wistar se dividieron en cuatro grupos de ocho semanas: Control: recibieron dieta equilibrada, mantenido sedentaria; Control Complementado: La suplementacion con creatina recibido (2%) en la dieta equilibrada, sedentaria mantenido; Trained: corriendo en una cinta en la intensidad de maximo estado estable de lactato y recibio el grupo de dieta equilibrada y grupo Treinado Complementado: corriendo sobre una cinta rodante a una intensidad maxima de lactato estable y recibieron la suplementacion con creatina (2%) en una dieta equilibrada. El consumo de agua aumenta y reduccion de la ganancia de peso corporal en la formacion y complementado. En el musculo soleo, la oxidacion de la glucosa aumento en ambos grupos suplementados. La produccion de los niveles de lactato y de glucosa durante la prueba de tolerancia a la glucosa disminuida en la formacion y complementado. La suplementacion con creatina en conjunto con el entrenamiento fisico mejora el metabolismo de la glucosa en el musculo de los ratones.O objetivo deste estudo foi avaliar o efeito da suplementacao de creatina na dieta sobre indicadores do metabolismo glicidico musculoesqueletico de ratos exercitados. Quarenta ratos Wistar adultos foram divididos em quatro grupos por oito semanas: Controle: receberam dieta balanceada, mantidos sedentarios; Controle Creatina: receberam suplementacao de creatina (2%) na dieta balanceada, mantidos sedentarios; Treinado: correram em esteira na intensidade da maxima fase estavel de lactato e receberam a dieta balanceada e grupo Treinado Suplementado: correram em esteira na intensidade da maxima fase estavel de lactato e receberam suplementacao de creatina (2%) na dieta balanceada. A ingestao hidrica aumentou e o ganho de massa corporal reduziu no grupo treinado e suplementado. No musculo soleo, a oxidacao de glicose aumentou em ambos os grupos suplementados. A producao de lactato e a glicemia durante teste de tolerância a glicose diminuiram no grupo treinado e suplementado. A suplementacao com creatina em conjunto com treinamento fisico melhorou metabolismo de glicidico muscular dos ratos.