Spatial memory in sedentary and trained diabetic rats: molecular mechanisms.

Diabetes mellitus is a chronic disease that has been associated with memory loss, neurological disorders, and Alzheimer's disease. Some studies show the importance of physical exercise to prevent and minimize various neurological disorders. It is believed that the positive effects of exercise on brain functions are mediated by brain insulin and insulin-like growth factor-1 (IGF-1) signaling. In this study, we investigate the role of swimming exercise training on hippocampus proteins related to insulin/IGF-1 signaling pathway in Type 1 diabetic rats and its effects on spatial memory. Wistar rats were divided into four groups namely sedentary control, trained control, sedentary diabetic (SD), and trained diabetic (TD). Diabetes was induced by Alloxan (ALX) (32 mg/kg b.w.). The training program consisted in swimming 5 days/week, 1 h/day, per 6 weeks, supporting an overload corresponding to 90% of the anaerobic threshold. We employed ALX-induced diabetic rats to explore learning and memory abilities using Morris water maze test. At the end of the training period, the rats were sacrificed 48 h after their last exercise bout when blood samples were collected for serum glucose, insulin, and IGF-1 determinations. Hippocampus was extracted to determinate protein expression (IR, IGF-1R, and APP) and phosphorylation (AKT-1, AKT-2, Tau, and ß-amyloide proteins) by Western Blot analysis. All dependent variables were analyzed by two-way analysis of variance with significance level of 5%. Diabetes resulted in hyperglycemia and hypoinsulinemia in both SD and TD groups (P < 0.05); however, in the training-induced group, there was a reduction in blood glucose in TD. The average frequency in finding the platform decreased in SD rats; however, exercise training improved this parameter in TD rats. Aerobic exercise decreased Tau phosphorylation and APP expression, and increased some proteins related to insulin/IGF-1 pathway in hippocampus of diabetic rats. Thus, these molecular adaptations from exercise training might contribute to improved spatial learning and memory in diabetic organisms.

Influência da suplementação com creatina em indicadores de metabolismo da glucose no músculo esquelético de ratos exercitados / Influencia de la suplementación con creatina sobre indicadores del metabolismo de la glucosa en el músculo esquelético de ratas ejercitadas / Influence of creatine supplementation on indicators of glucose metabolism in skeletal muscle of exercised rats

The purpose of this study was to evaluate the effect of creatine supplementation in the diet on indicators of glucose metabolism in skeletal muscle of exercised rats. Forty Wistar adult rats were distributed into four groups for eight weeks: 1) Control: sedentary rats that received balanced diet; 2) Creatine control: sedentary rats that received supplementation of 2% creatine in the balanced diet; 3) Trained: rats that ran on a treadmill at the Maximal Lactate Steady State and received balanced diet; and 4) Supplemented-trained: rats that ran on a treadmill at the Maximal Lactate Steady State and received creatine supplementation (2%) in the balanced diet. The hydric intake increased and the body weight gain decreased in the supplemented-trained group. In the soleus muscle, the glucose oxidation increased in both supplemented groups. The production of lactate and glycemia during glucose tolerance test decreased in the supplemented-trained group. Creatine supplementation in conjunction with exercise training improved muscular glycidic metabolism of rats.

O objetivo deste estudo foi avaliar o efeito da suplementação de creatina na dieta sobre indicadores do metabolismo glicídico musculoesquelético de ratos exercitados. Quarenta ratos Wistar adultos foram divididos em quatro grupos por oito semanas: Controle: receberam dieta balanceada, mantidos sedentários; Controle Creatina: receberam suplementação de creatina (2%) na dieta balanceada, mantidos sedentários; Treinado: correram em esteira na intensidade da máxima fase estável de lactato e receberam a dieta balanceada e grupo Treinado Suplementado: correram em esteira na intensidade da máxima fase estável de lactato e receberam suplementação de creatina (2%) na dieta balanceada. A ingestão hídrica aumentou e o ganho de massa corporal reduziu no grupo treinado e suplementado. No músculo sóleo, a oxidação de glicose aumentou em ambos os grupos suplementados. A produção de lactato e a glicemia durante teste de tolerância à glicose diminuíram no grupo treinado e suplementado. A suplementação com creatina em conjunto com treinamento físico melhorou metabolismo de glicídico muscular dos ratos.

El objetivo de este estudio fue evaluar el efecto de la suplementación con creatina en la dieta sobre indicadores del metabolismo de glucosa en el músculo esquelético 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 suplementación con creatina recibido (2%) en la dieta equilibrada, sedentaria mantenido; Trained: corriendo en una cinta en la intensidad de máximo estado estable de lactato y recibió el grupo de dieta equilibrada y grupo Treinado Complementado: corriendo sobre una cinta rodante a una intensidad máxima de lactato estable y recibieron la suplementación con creatina (2%) en una dieta equilibrada. El consumo de agua aumenta y reducción de la ganancia de peso corporal en la formación y complementado. En el músculo sóleo, la oxidación de la glucosa aumentó en ambos grupos suplementados. La producción de los niveles de lactato y de glucosa durante la prueba de tolerancia a la glucosa disminuida en la formación y complementado. La suplementación con creatina en conjunto con el entrenamiento físico mejora el metabolismo de la glucosa en el músculo de los ratones.

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

BACKGROUND: Obesity, 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. METHODS: Twenty 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%. RESULTS: The T group showed lower body weight gain, FFA concentrations, fat accumulation, hepatic lipogenic rate and insulin resistance. CONCLUSION: The 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.

Perfil lipídico de ratos com hipertireoidismo induzido: efeitos do exercício físico agudo / Lipid profile of rats with induced hyperthyroidism: effects of acute exercise

Este estudo teve como objetivo analisar o perfil lipídico de ratos Wistar com hipertireoidismo induzido em repouso e após exercício físico agudo. Foram utilizados 28 ratos machos Wistar, divididos em hipertireoidismo (H; induzido com tiroxina) e controle (C). Metade dos animais de cada grupo foi sacrificada em repouso. A outra metade foi submetida, imediatamente antes do sacrifício, à sessão única de exercício de natação, por 20 minutos (carga de 5% em relação ao peso corporal). Para as comparações entre os grupos utilizou-se Teste T de Student’s e ANOVA Two-Way, seguida de post-hoc de Newman-Keuls. O grupo H apresentou menor peso do tecido adiposo nas regiões mesentérica, retroperitoneal e subcutânea, comparado com o grupo C, o que reflete a perda de peso corporal neste grupo. Menores valores de colesterol total, LDL e HDL, na condição em repouso, foram observados no grupo H. Após o exercício agudo houve um incremento estatisticamente significativo de glicose em ambos os grupos, bem como, redução dos níveis de triglicerídeos no grupo C (p<0,05). As concentrações de lipídios totais nocoração foram menores em repouso para o grupo H quando comparado com o grupo C. Após sessão aguda de exercício físico essas concentrações se elevaram no grupo H (p<0,05). A droga utilizada induziu características de hipertireoidismo, associadas ao perfil lipídico, em ratos Wistar. O exercício físico agudo não alterou o perfil lipídico dos animais com hipertireoidismo experimental, exceto os lipídios totais do coração. A partir dos achados do presente estudo, trabalhos futuros poderão utilizar intensidade de exercício físico similar (5% do peso corporal) e analisar outros parâmetros metabólicos relacionados a essa patologia em ratos.

The aim of this study was to analyze the lipid profile of rats Wistar with hyperthyroidism at rest and after an acute exercise session. Twenty-eight male Wistar rats were divided into hyperthyroidism (H; induced with tiroxin), and control (C). Half of the animals of each group were sacrificed at rest. The other half was submitted, immediately before the sacrifice, to an a session of swimming exercise for 20 minutes. For the comparisons among the groups Student's t test and ANOVA Two-way test were used, following by post-hoc of Newman-Keuls. The H group presented lower adipose tissue weight of the mesenteric, retroperitoneal and subcutaneous areas compared with the group C, which reflects the loss of corporal weight observed in this group. Lower values of the total cholesterol, LDL and HDL were observed in the H group at rest condition. After exercise there was a glucose increment in both groups, and reduction of the triglycerides levels in the C group (p<0.05). The concentrations of total lipids in the heart were lower at rest for the H group compared with the C group. After the acute session of physical exercise those concentrations enhanced in the H group (p<0.05). The drug used was efficient in inducing characteristics of hyperthyroidism, associated to the lipid profile, in Wistar rats and that the acute session of exercise did not changed the lipid profile of the animals with experimental hyperthyroidism. This is important, because future studies may use similar intensity of physical exercise (5% body weight) and analyze other metabolic parameters associated with this pathology in rats.

Alterações bioquímicas e hepáticas em ratos submetidos à uma dieta hiperlipídica/hiperenergética / Hepatic biochemical changes in rats submitted to a high-fat/high-energy diet

OBJETIVO: O presente estudo teve como objetivo analisar as alterações bioquímicas hepáticas decorrentes da administração de uma dieta hiperlipídica/hiperenergética em ratos. MÉTODOS: Foram utilizados 20 ratos (Wistar) com 90 dias de idade divididos em dois grupos, grupo-controle constituída por ratos eutróficos alimentados com dieta comercial para roedores e grupo-dieta constituída por ratos submetidos a uma dieta hiperlipídica/hiperenergética semi purificada feita com 35% de gordura sendo 31% de origem animal a qual possui 39% de gordura saturada e 4% de origem vegetal (óleo de soja). Os animais do grupo-controle foram mantidos com dieta comercial Purina® e o grupo-dieta com uma dieta hiperlipídica/hiperenergética constituída por 35% de gordura. Após 60 dias de administração de uma dieta hiperlipídica/hiperenergética, analisou-se massa corporal, sensibilidade à insulina, concentração sérica de glicose, insulina e ácidos graxos livres e medida do nível de triglicerídeos, lipídeos totais e atividade lipogênica hepática. RESULTADOS: O grupo-dieta apresentou maior massa corporal e resistência à insulina. No sangue não foram encontradas diferenças entre os grupos para os níveis de glicose. Foi evidenciada maior concentração de insulina e de ácidos graxos livres no soro para o grupo-dieta. No fígado o nível de lipídeos totais, triglicerídeos e taxa lipo-gênica foram superiores às do grupo-controle. CONCLUSÃO: Portanto, nossos achados demonstram que dois meses de ingestão de dieta hiperlipídica/hiperenergética por ratos adultos eleva o peso corporal, ácidos graxos livres hepáticos, diminui a sensibilidade à insulina, demostrando sinais típicos de doença hepática gordurosa não-alcoólica.

OBJECTIVE: The present study analyzed the biochemical and hepatic changes in adult rats fed a high-fat diet for two months. METHODS: Twenty Wistar rats 90 days old were divided into two groups, a control group consisting of normal weight rats fed a commercial rat chow and a diet group consisting of normal weight rats submitted to a semi-purified high-fat, high-energy diet. The animals in control group were kept on a commercial Purina® chow and those in diet group on a high-fat/high-energy diet containing 35% fat, of which 31% were from animal source (39% saturated fat) and 4% were from vegetable source (soybean oil). After 60 days of this experimental diet, the following were assessed: body weight, insulin sensitivity, blood glucose, serum insulin and free fatty acids, triglycerides, total lipids and hepatic lipogenic activity. RESULTS: Diet group presented higher body mass and insulin resistance. Blood glucose did not differ between the groups. A higher level of serum insulin and free fatty acids were found in diet group. Total lipids, triglycerides and lipogenic rate were also higher in group D. CONCLUSION: Therefore, the present findings demonstrate that two months of a high-fat/high-energy diet increases the body weight and hepatic free fatty acids and decreases insulin sensitivity of adult rats, typical signs of non-alcoholic fatty liver disease.

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

BACKGROUND: Type 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. METHODS: Wistar 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. RESULTS: At 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 animals CONCLUSION: Thus, 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.

Efeitos do treinamento aeróbio sobre o perfil lipídico de ratos com hipertireoidismo / Effects of aerobic training on the lipid profile of rats with hyperthyroidism

Há poucos estudos analisando a importante relação entre o exercício físico, agudo e crônico, e alterações metabólicas decorrentes do hipertireoidismo. O objetivo do presente estudo foi analisar o efeito de quatro semanas de treinamento aeróbio sobre o perfil lipídico de ratos com hipertireoidismo experimental. Foram utilizados 45 ratos da linhagem Wistar, divididos aleatoriamente em quatro grupos: Controle Sedentário (CS) - administrados com salina durante o período experimental, não praticaram exercício físico (n = 12); Controle Treinado (CT) - administrados com salina, participaram do treinamento (n = 11); Hipertireoidismo Sedentário (HS) - induzidos ao hipertireoidismo, não praticaram exercício físico (n = 12); e Hipertireoidismo Treinado (HT) - induzidos ao hipertireoidismo, participaram do treinamento (n = 10). O treinamento aeróbio teve duração de quatro semanas, cinco vezes na semana, com duração de uma hora por sessão. Após o término do período experimental todos os ratos foram anestesiados em câmara de CO2 até sua sedação. Coletaram-se amostras de sangue para dosagem de colesterol total, triglicerídeos, HDL-colesterol e LDL-colesterol e hormônio T3; e amostras do coração, fígado, músculo gastrocnêmio e tecido adiposo das regiões mesentérica, retroperitonial e subcutânea para pesagem e dosagem de triglicerídeos. Para análise estatística utilizou-se ANOVA two-way, seguida do post hoc LSD de Fischer. Observaram-se menores valores de AGL no grupo HS quando comparado ao CS. O grupo HS teve nível de triglicerídeos significativamente superior nas regiões mesentérica, do gastrocnêmio e retroperitonial quando comparado com os grupos CS e CT, e apenas o tecido adiposo da região retroperitonial apresentou diferenças significativas na qual o grupo HT apresentou menor peso quando comparado com o grupo CS. Pode-se concluir que os ratos hipertireoidicos apresentaram perfil lipídico diferente dos ratos controle, e o treinamento aeróbio em ratos Wistar pode ter alterado o perfil lipídico dos animais com hipertireoidismo experimental quando comparados com o grupo sedentário e grupos controle.

The relationship between physical exercise, either acute or chronic, and metabolic changes resulting from hyperthyroidism has been little studied in the literature. The aim of this study was to analyze the effects of four weeks of aerobic training on the lipid profile of rats with experimental hyperthyroidism. 45 Wistar rats were randomly divided in four groups: Sedentary Control (SC) -administered saline solution during the experimental period and did not exercise (n = 12); Trained Control (TC) - administered saline solution and underwent physical training (n = 11); Sedentary Hyperthyroidism (SH) - induced hyperthyroidism and did not exercise (n=12) and Trained Hyperthyroidism (TH) - induced hyperthyroidism and underwent physical training (n = 10). The aerobic training lasted one hour per day, five times a week, during four weeks. After the training period, the rats were anesthetized in CO2 chamber until their sedation. The blood was collected for total cholesterol, triglycerides, HDL-cholesterol and LDL-cholesterol and serum T3 dosage. Additionally, heart, liver, gastrocnemius muscle and adipose tissue of the mesenteric, retroperitoneal and subcutaneous regions were collected for weighing and triglycerides dosage. Two-way ANOVA, followed by Fisher LSD Post-Hoc was applied for statistical analysis. Lower AGL values were observed in the SH group when compared with SC. The TH group presented lower weight of adipose tissue in the retroperitoneal compared with the SC group. The triglycerides concentrations in the mesenteric, gastrocnemius and retroperotoneal regions were higher in SH group compared with the SC and TC groups. Therefore, it can be concluded that the hyperthyroidism rats presented lipid profile different from the control rats and that aerobic training in rats may have altered the lipid profile of animals with experimental hyperthyroidism compared with the sedentary and control groups.

Fructose-rich diet leads to reduced aerobic capacity and to liver injury in rats.

The main purpose of this research was to investigate the alterations in the aerobic capacity and appearance of metabolic alterations in Wistar rats fed on fructose-rich diet. We separated twenty-eight rats into two groups according to diet: a control group (C) (balanced diet) and a fructose-rich diet group (F). The animals were fed these diets for 60 d (d 120 to 180). We performed insulin, glucose as well as a minimum lactate test, at d 120 and 180. At the end of the experiment, sixteen animals were euthanized, and the following main variables were analysed: aerobic capacity, the serum aspartate aminotransferase (AST) to alanine aminotransferase (ALT) ratio, serum and liver triglyceride concentrations, serum and liver thiobarbituric acid reactive substance (TBARS) concentrations, serum and liver catalase and superoxide dismutase (SOD) activity and haematoxylin-eosin histology (HE) in hepatocytes. The remaining twelve animals were submitted to an analysis of their hepatic lipogenic rate. The animals fed a fructose-rich diet exhibited a reduction in aerobic capacity, glucose tolerance and insulin sensitivity and increased concentrations of triglycerides and TBARS in the liver. Catalase and SOD activities were reduced in the livers of the fructose-fed animals. In addition, the serum AST/ALT ratio was higher than that of the C group, which indicates hepatic damage, and the damage was confirmed by histology. In conclusion, the fructose-rich diet caused significant liver damage and a reduction in insulin sensitivity in the animals, which could lead to deleterious metabolic effects.

Metabolic syndrome markers in wistar rats of different ages.

In recent decades, metabolic syndrome has become a public health problem throughout the world. Longitudinal studies in humans have several limitations due to the invasive nature of certain analyses and the size and randomness of the study populations. Thus, animal models that are able to mimic human physiological responses could aid in investigating metabolic disease. Thus, the present study was designed to analyze metabolic syndrome markers in albino Wistar rats (Rattus norvegicus) of different ages. The following parameters were assessed at two (young), four ( adult), six (adult), and twelve (mature) months of age: glucose tolerance (glucose tolerance test); insulin sensitivity (insulin tolerance test); fasting serum glucose, triglycerides, total cholesterol, HDL cholestero, and LDL cholesterol concentrations; glucose uptake in isolated soleus muscle; and total lipid concentration in subcutaneous, mesenteric, and retroperitoneal adipose tissue. We found that aging triggered signs of metabolic syndrome in Wistar rats. For example, mature rats showed a significant increase in body weight that was associated. In addition, mature rats showed an increase in the serum concentration of triglycerides, total cholesterol, and LDL cholesterol, which is characteristic of dyslipidemia. There was also an increase in serum glucose compared with the younger groups of animals. Therefore, aging Wistar rats appear to be an interesting model to study the changes related to metabolic syndrome.

Effects of swimming training on tissue glycogen content in experimental thyrotoxic rats.

Thyrotoxicosis, a condition in which there is an excessive amount of circulating thyroid hormones, leads to reduced glycogen content in different tissues. In this study we analyzed the effects of aerobic swimming training on liver, heart, and skeletal muscle glycogen content in experimentally induced thyrotoxicosis. Wistar male rats were divided into euthyroid sedentary (ES, n = 12), euthyroid trained (ET, n = 11), thyrotoxic sedentary (TS, n = 12), and thyrotoxic trained (TT, n = 10) groups. Thyrotoxic groups received daily i.p. doses of T4 (sodium levothyroxine, 25 µg/100 g body mass) through the experimental period, and trained groups swam for 1 h at 80% of the aerobic-anaerobic transition intensity, 5 days/week for 4 weeks. Heart and liver glycogen stores were ∼30% lower in T4 treated compared with nontreated groups, but were not changed by training status. On the other hand, glycogen content in mixed fiber type gastrocnemius of TT was 1.5- to 2.3-fold greater than those in other groups, whereas no significant differences were found for the slow soleus muscle. Increased gastrocnemius but not soleus, liver, or heart glycogen indicates that in mild long-term thyrotoxicosis chronic swimming affects glycogen stores in a tissue-specific manner.

Feed restriction and a diet's caloric value: The influence on the aerobic and anaerobic capacity of rats.

BACKGROUND: The influence of feed restriction and different diet's caloric value on the aerobic and anaerobic capacity is unclear in the literature. Thus, the objectives of this study were to determine the possible influences of two diets with different caloric values and the influence of feed restriction on the aerobic (anaerobic threshold: AT) and anaerobic (time to exhaustion: Tlim) variables measured by a lactate minimum test (LM) in rats. METHODS: We used 40 adult Wistar rats. The animals were divided into four groups: ad libitum commercial Purina® diet (3028.0 Kcal/kg) (ALP), restricted commercial Purina® diet (RAP), ad libitum semi-purified AIN-93 diet (3802.7 Kcal/kg) (ALD) and restricted semi-purified AIN-93 diet (RAD). The animals performed LM at the end of the experiment, 48 h before euthanasia. Comparisons between groups were performed by analysis of variance (p < 0,05). RESULTS: At the end of the experiment, the weights of the rats in the groups with the restricted diets were significantly lower than those in the groups with ad libitum diet intakes. In addition, the ALD group had higher amounts of adipose tissue. With respect to energetic substrates, the groups subjected to diet restriction had significantly higher levels of liver and muscle glycogen. There were no differences between the groups with respect to AT; however, the ALD group had lower lactatemia at the AT intensity and higher Tlim than the other groups. CONCLUSIONS: We conclude that dietary restriction induces changes in energetic substrates and that ad libitum intake of a semi-purified AIN-93 diet results in an increase in adipose tissue, likely reducing the density of the animals in water and favouring their performance during the swimming exercises.

Influência do exercício agudo no metabolismo de ratos com hipertireoidismo / Influence of acute exercise on the metabolism of rats with hyperthyroidism

Diversas investigações são encontradas na literatura apresentando características de intolerância ao exercício em indivíduos com hipertireoidismo. Apesar do apontamento de alguns motivos que explicariam tal fenômeno, poucos analisam as influências do exercício físico agudo no metabolismo glicídico e protéico de animais com esta patologia. Diante deste contexto, o objetivo do presente estudo foi analisar a influência de uma sessão de exercício físico aeróbio no metabolismo glicídico e protéico de ratos hipertireoideanos. Para tal, foram utilizados 26 ratos que foram mantidos em biotério com alimentação, temperatura ambiente e ciclo claro/escuro controlados, distribuídos nos seguintes grupos: controle repouso (CR) e controle exercício agudo (CA); hipertireoidismo repouso (HR) e hipertireoidismo exercício agudo (HA). Os animais do grupo hipertireoidismo foram induzidos ao quadro patológico por meio da administração de levotiroxina sódica por um período de 10 dias. Foi registrado o peso corporal, ingestão hídrica e alimentar, além de analisadas algumas variáveis teciduais e séricas. Com auxílio da estatística paramétrica e não paramétrica foram encontradas alterações no peso corporal e em variáveis séricas e teciduais quando comparados os grupos. Foi encontrado maior peso corporal nos grupos controle em relação aos animais com hipertireoidismo. A albumina e as proteínas mostraram-se maiores nos animais controle. A glicose apresentou reduzida concentração no HR e elevada no CA. A concentração de glicogênio apresentou-se elevada no tecido muscular para HR e hepático para CR. A razão proteína/DNA não sofreu alterações no tecido muscular, enquanto apresentou algumas modulações significativas no tecido hepático. Diante das modulações séricas e teciduais encontradas, concluímos que o exercício físico agudo parece ser capaz de alterar a dinâmica metabólica glicídica e protéica, sérica e tecidual em ratos com hipertireoidismo.

Several investigations are found in the literature showing characteristics of exercise intolerance in patients with hyperthyroidism. Despite the appointment of some reasons that explain this phenomenon, few studies analyze the influences of acute physical exercise on glicidic and proteic metabolism in animals with this disease. In this context, the objective of this study was to analyze the influence of an acute bout of aerobic exercise on glicidic and proteic metabolism in rats with hyperthyroidism. For this purpose, were used 26 rats, kept in cages with food, temperature and light/dark cycle controlled, divided into the following groups: resting control (CR) and control acute exercise (CA); hyperthyroidism rest (HR) and hyperthyroidism acute exercise (HA). The animals of group hyperthyroidism were induced by the pathological status with the administration of levothyroxine for a 10 d period. It was recorded the body weight, food and water intake, and some tissues and serum variables were analyzed. Using parametric and non parametric statistical tools, changes were found in body weight, besides serum and tissue variables when comparing the groups. Was found higher body weight in the control groups when compared to hyperthyroidism groups. The albumin and protein were higher in control animals. Glucose concentration was reduced in HR and elevated in CA. The glycogen concentration was increased in muscle tissue and liver for HR in relation to CR. The protein content, DNA and ratio protein/DNA have not changed in muscle tissue, while some showed significant modulations in liver tissue. Given the modulations found in serum and tissue, we conclude that acute physical exercise seems to be able to change the dynamics of protein and carbohydrate metabolism, serum and tissue in rats with hyperthyroidism.

A influência do ultrassom e do treinamento físico sobre os triglicérides séricos e intramusculares em ratos diabéticos experimentais / The influence of ultrasound and physical trainning on serum and muscle tryglicerides in experimental diabetic rats

O ultrassom terapêutico é visto hoje como um dos recursos mais utilizados na prática da medicina clínica e o exercício físico é consolidado como uma terapêutica eficaz e eficiente em diversos casos, porém ainda pouco investigados em conjunto; por isso, o presente trabalho tem como objetivo analisar a influência do ultrassom e do exercício físico sobre as concentrações de triglicérides sérico e intramusculares (IMTG) em ratos diabéticos experimentais. Foram utilizados ratos Wistar adultos divididos em oitos grupos: Diabéticos Sedentários (DS), Diabéticos Treinados (DT), Diabéticos Sedentários e Ultrassom (DSUs), Diabéticos Treinados e Ultrassom (DTUs), Controle Sedentário (CS), Controle Treinado (CT), Controle Sedentário e Ultrassom (CSUs), Controle Treinado e Ultrassom (CTUs). O protocolo de treinamento constituía de natação cinco dias por semana, 30 minutos, por dia com uma carga máxima equivalente a 8 por cento da massa corporal, durante três semanas. A terapia ultrassônica foi realizada cinco dias por semana, durante duas semanas, com intensidade de 0,2W/cm² e frequência de 1,0MHz. Não houve diferenças significativas nos triglicerídeos séricos e nos músculo Tibial Anterior e Gastrocnêmio. Para o músculo Sóleo as concentrações dos grupos diabéticos foram menores comparados com as dos grupos controles e também entre os grupos DT e DTUs comparado com DS e DSUS, sendo que treinados apresentaram as menores concentrações. O ultrassom pulsado na intensidade proposta não influenciou as concentrações séricas de triglicerídeos nem de IMTG. Porém o exercício físico foi eficaz em reduzir IMTG no músculo Sóleo.

Therapeutic ultrasound is seen today as one of the most useful resources in the practice of clinical medicine and physical exercise is consolidated as an effective and efficient therapeutics in several cases; however, they are still little investigated when associated. Therefore, the present work has as the aim to analyze the influences of ultrasound and physical exercise on serum and muscle triglycerides concentrations in experimental diabetes rats. Adult Wistar rats were used and divided in eight groups: Sedentary Diabetics (SD), Trained Diabetics (TD), Sedentary Diabetic and Ultrasound (SDUs), Trained Diabetic and Ultrasound (TDUs), Sedentary Control (SC), Trained Control (TC), Sedentary and Ultrasound Controls (SUCs), Trained Control and Ultrasound (TCUs). The training protocol was composed of swimming exercise five days a week, 30 daily minutes and with maximum load of 8 percent of body mass during three weeks. The ultrasound therapy was performed five days a week, for two weeks, with intensity of 0.2W/cm² and frequency of 1.0MHz. No significant differences were observed in the serum triglycerides or in the tibialis anterior and gastrocnemius muscles. Concerning the soleus muscle, the diabetic groups showed lower concentrations compared to the control groups and TD, and TDUs groups showed lower concentrations compared to SD and SDSU, with the trained groups presenting the lowest concentrations. The pulsed ultrasound in the intensity investigated did not influence serum triglycerides or IMTG. However, exercise was effective in reducing soleus muscle triglycerides.

Aerobic capacity of rats recovered from fetal malnutrition with a fructose-rich diet.

The objective of this study was to analyze the aerobic capacity, through the maximal lactate steady-state (MLSS) protocol, of rats subjected to fetal protein malnutrition and recovered with a fructose-rich diet. Pregnant adult Wistar rats that were fed a balanced (17% protein) diet or a low-protein (6% protein) diet were used. After birth, the offspring were distributed into groups according to diet until 60 days of age: balanced (B), balanced diet during the whole experimental period; balanced-fructose (BF), balanced diet until birth and fructose-rich diet (60% fructose) until 60 days; low protein-balanced (LB), low-protein diet until birth and balanced diet until 60 days; and low protein-fructose (LF), low protein diet until birth and fructose-rich diet until 60 days. It was verified that the fructose-rich diet reduced body growth, mainly in the BF group. There was no difference among the groups in the load corresponding to the MLSS (B, 7.5+/-0.5%; BF, 7.4+/-0.6%; LB, 7.7+/-0.4%; and LF, 7.7+/-0.6% relative to body weight). However, the BF group presented higher blood lactate concentrations (4.8+/-0.9 mmol.L(-1)) at 25 min in the load corresponding to the MLSS (B, 3.2+/-0.9 mmol.L(-1); LB, 3.4+/-0.9 mmol.L(-1); and LF, 3.2+/-1.0 mmol.L(-1)). Taken together, these results indicate that the ability of young rats to perform exercise was not altered by intrauterine malnutrition or a fructose-rich diet, although the high fructose intake after the balanced diet in utero increased blood lactate during swimming exercises in rats.

Efeitos em curto prazo da aplicação de aloxana para indução de diabetes em ratos Wistar / Effects in short-term of alloxan application to diabetes induction in Wistar rats

O presente estudo teve como objetivo verificar a ação da aloxana em parâmetros metabólicos e do sistema imune 24 e 192 horas após sua aplicação em ratos Wistar. Para isso, oito ratos foram mantidos em jejum de 12 horas e receberam aloxana monoidratada, Sigma (32 mg/kg de peso corporal) via endovenosa. Foram registrados os valores de massa corporal, ingestão hídrica e alimentar e realizada a contagem de leucócitos totais previamente, 24 e 192 horas após a aplicação da aloxana. As análises de glicemia e trigliceridemia foram realizadas previamente e 192 horas após a aplicação da aloxana. Após 24 horas, a aplicação da aloxana causou aumento da ingestão hídrica e redução da massa corporal, ingestão alimentar e contagem de leucócitos. Na avaliação realizada 192 horas após a aplicação da aloxana houve recuperação da ingestão alimentar e contagem de leucócitos. Por outro lado, neste período houve aumento da glicemia e ingestão hídrica além de redução da massa corporal. Isso indica que parte dos sinais de diabetes causados pela aloxanamanifesta-se em curto prazo da administração da droga.

The present study aimed to verify action of alloxan in metabolic and immune parameters after 24 and 192 hours of the injection in Wistar rats. Thus, eight rats were fasted and received monohidrated alloxan Sigma (32 mg/kg body weight) via endovenous. Glycemia and trglyceridemia analyzes were performed before and 192 hours after alloxan application. After 24 hours, alloxan application increased water intake and decreased body mass, food intake and leucocytes counting. 192 hours after alloxan application, there was a recuperation in food intake and leucocytes counting. On the other hand, in this period there was an increase of glycemia and water intake and reduction of body mass. These results indicate that some of diabetic signs caused by alloxan occur in short-term after drug administration.

Consumo de frutose e exercício físico, impacto na síndrome metabólica / Fructose Consumption and physical exercise, the impact on metabolic syndrome

Nas últimas duas décadas, a síndrome metabólica está no foco das diversas agências de saúde mundiais. Compreendendo entre os aspectos mais importantes a intolerância à glicose e a resistência à insulina, outras desordens vêm sendo enquadradas nessa categoria. A esteatose hepática não alcoólica emerge como um dos componentes dessa síndrome. Diversos estudos apontam o aumento do consumo de frutose associado ao sedentarismo ao aparecimento da esteatose hepática. A partir dessa premissa, a presente revisão objetivou-se na busca de estudos que apontem o papel do exercício físico como importante arma no tratamento e na prevenção da esteatose hepática não alcoólica.

In the last two decades, the metabolic syndrome is in focus of many health agencies worldwide. Understanding among the most important glucose intolerance and insulin resistance, other disorders have been framed in this category. The non-alcoholic hepatic steatosis appears to be one of the components of this syndrome. Several studies point to the increased consumption of fructose linked to the onset of sedentary steatohepatitis. From that premise, this review aimed to the search for studies that suggest the role of exercise as an important weapon in the treatment and prevention of non-alcoholic hepatic steatosis.