Effects of 12 Weeks of Daily Melatonin Administration on Inflammatory Markers and Adipose Tissue Mass of Rats under Hypoestrogenism.

Background and Objectives: The hormonal state of hypoestrogenism is associated with the accumulation of white adipose tissue, which can induce an increase in pro-inflammatory markers, leading to progressive health complications. Melatonin can act on adipose tissue mass, promoting its reduction and influencing inflammation, reducing IL-6 and releasing IL-10, pro- and anti-inflammatory markers, respectively. However, the role of melatonin regarding such parameters under the context of hypoestrogenism remains unknown. The aim of this study was to determine the effect of 12 weeks of hypoestrogenism and melatonin on white adipose tissue mass and circulating levels of IL-6, IL-10, TGF-ß-1, and leukotriene C4 (LTC4). Materials and Methods: The animals (Wistar rats with sixteen weeks of age at the beginning of the experiment) under hypoestrogenism were submitted to the surgical technique of bilateral ovariectomy. The animals received melatonin (10 mg·kg-1) or vehicles by orogastric gavage every day for 12 weeks and administration occurred systematically 1 h after the beginning of the dark period. White adipose tissue (perigonadal, peritoneal, and subcutaneous) was collected for mass recording, while blood was collected for the serum determination of IL-6, IL-10, TGF-ß-1, and LTC4. Results: Hypoestrogenism increased the perigonadal and subcutaneous mass and IL-6 levels. Melatonin kept hypoestrogenic animals in physiological conditions similar to the control group and increased thymus tissue mass. Conclusions: Hypoestrogenism appears to have a negative impact on white adipose tissue mass and IL-6 and although melatonin commonly exerts a significant effect in preventing these changes, this study did not have a sufficiently negative impact caused by hypoestrogenism for melatonin to promote certain benefits.

Influence of Acute Melatonin Administration on Human Physical Performance: A Systematic Review.

CONTEXT: Melatonin is an ancient molecule with a wide range of functions in mammals, such as antioxidant, anti-inflammatory, and hypothermic effects among others. However, the influence of acute melatonin administration on human physical performance is debatable. OBJECTIVE: To summarize available data from controlled trials about the effects of acute melatonin administration on human physical performance, especially with respect to strength, power, speed, and short- and long-term continuous exercise. DATA SOURCES: A systematic search of the PubMed, Web of Science, Scopus, Embase, and Cochrane databases up to December 10, 2021, was conducted using specified keywords and Boolean operators ("melatonin" AND "exercise OR circuit-based exercise OR plyometric exercise OR exercise tolerance OR exercise test"). STUDY SELECTION: Only controlled studies in the English language and with humans were accepted. STUDY DESIGN: Systematic review. LEVEL OF EVIDENCE: Level 1. DATA EXTRACTION: Participants' characteristics (sex, age, body mass, height and fat percentage), melatonin dose and administration time, and outcomes from the performance trial were extracted. RESULTS: A total of 10 studies were identified after the screening process. Overall, melatonin did not change speed or short-term continuous exercise performances. However, in relation to strength and power, the results are debatable since 5 articles showed no difference, while another 2 pointed to a decrease in performance. In terms of performance improvement, only 1 study reported an increase in balance and another in long-term continuous exercise performance in nonathletes, with no advantage found for athletes. CONCLUSION: Melatonin did not cause any significant change in strength, speed, power, and short-term continuous exercise performances. In fact, it led to reduced strength and power performances in specific tests. On the other hand, melatonin seems to have improved balance and long-term continuous exercise performance, at least in nonathletes. More investigations are required to corroborate these findings.

Systemic and local inflammatory response after implantation of biomaterial in critical bone injuries.

PURPOSE: To evaluate inflammatory response in critical bone injuries after implantation of the biomaterial composed of hydroxyapatite (HA)/poly (lactic-coglycolic acid) (PLGA)/BLEED. METHODS: Forty-eight male Wistar rats (280 ± 20 grams) were divided into two groups: control group (CG), in which the animals do not receive any type of treatment; and biomaterial group (BG), in which the animals received the HA/PLGA/BLEED scaffold. Critical bone injury was induced in the medial region of the skull calotte with the aid of a trephine drill 8 mm in diameter. The biomaterial was implanted in the form of 1.5-mm thick scaffolds. Serum and calotte were collected at one, three and seven days. RESULTS: Biomaterial had a significant effect on the morphological structure of the bone, accelerating osteoblast activation within three days, without causing exacerbated systemic inflammation. In addition, quantitative real-time polymerase chain reaction (qRT-PCR) analysis showed that BG induced upregulation of osteogenic genes such as runt-related transcription factor 2, and stimulated genes of inflammatory pathways such as tumor necrosis factor-α, on the first day without overexpressing genes related to bone matrix degradation, such as tissue inhibitor of metalloproteinases-1 and matrix metalloproteinase-9. CONCLUSIONS: The HA/PLGA/BLEED® association can be used as a bone graft to aid bone repair, as it is capable of modulating expression of important genes at this stage of the repair process.

Systemic and local inflammatory response after implantation of biomaterial in critical bone injuries

ABSTRACT Purpose: To evaluate inflammatory response in critical bone injuries after implantation of the biomaterial composed of hydroxyapatite (HA)/poly (lactic-coglycolic acid) (PLGA)/BLEED. Methods: Forty-eight male Wistar rats (280 ± 20 grams) were divided into two groups: control group (CG), in which the animals do not receive any type of treatment; and biomaterial group (BG), in which the animals received the HA/PLGA/BLEED scaffold. Critical bone injury was induced in the medial region of the skull calotte with the aid of a trephine drill 8 mm in diameter. The biomaterial was implanted in the form of 1.5-mm thick scaffolds. Serum and calotte were collected at one, three and seven days. Results: Biomaterial had a significant effect on the morphological structure of the bone, accelerating osteoblast activation within three days, without causing exacerbated systemic inflammation. In addition, quantitative real-time polymerase chain reaction (qRT-PCR) analysis showed that BG induced upregulation of osteogenic genes such as runt-related transcription factor 2, and stimulated genes of inflammatory pathways such as tumor necrosis factor-α, on the first day without overexpressing genes related to bone matrix degradation, such as tissue inhibitor of metalloproteinases-1 and matrix metalloproteinase-9. Conclusions: The HA/PLGA/BLEED® association can be used as a bone graft to aid bone repair, as it is capable of modulating expression of important genes at this stage of the repair process.

Melatonin Potentiates Exercise-Induced Increases in Skeletal Muscle PGC-1α and Optimizes Glycogen Replenishment.

Compelling evidence has demonstrated the effect of melatonin on exhaustive exercise tolerance and its modulatory role in muscle energy substrates at the end of exercise. In line with this, PGC-1α and NRF-1 also seem to act on physical exercise tolerance and metabolic recovery after exercise. However, the literature still lacks reports on these proteins after exercise until exhaustion for animals treated with melatonin. Thus, the aim of the current study was to determine the effects of acute melatonin administration on muscle PGC-1α and NRF-1, and its modulatory role in glycogen and triglyceride contents in rats subjected to exhaustive swimming exercise at an intensity corresponding to the anaerobic lactacidemic threshold (iLAn). In a randomized controlled trial design, thirty-nine Wistar rats were allocated into four groups: control (CG = 10), rats treated with melatonin (MG = 9), rats submitted to exercise (EXG = 10), and rats treated with melatonin and submitted to exercise (MEXG = 10). Forty-eight hours after the graded exercise test, the animals received melatonin (10 mg/kg) or vehicles 30 min prior to time to exhaustion test in the iLAn (tlim). Three hours after tlim the animals were euthanized, followed by muscle collection for specific analyses: soleus muscles for immunofluorescence, gluteus maximus, red and white gastrocnemius for the assessment of glycogen and triglyceride contents, and liver for the measurement of glycogen content. Student t-test for independent samples, two-way ANOVA, and Newman keuls post hoc test were used. MEXG swam 120.3% more than animals treated with vehicle (EXG; p < 0.01). PGC-1α and NRF-1 were higher in MEXG with respect to the CG (p < 0.05); however, only PGC-1α was higher for MEXG when compared to EXG. Melatonin reduced the triglyceride content in gluteus maximus, red and white gastrocnemius (F = 6.66, F = 4.51, and F = 6.02, p < 0.05). The glycogen content in red gastrocnemius was higher in MEXG than in CG (p = 0.01), but not in EXG (p > 0.05). In conclusion, melatonin was found to enhance exercise tolerance, potentiate exercise-mediated increases in PGC-1α, decrease muscle triglyceride content and increase muscle glycogen 3 h after exhaustive exercise, rapidly providing a better cellular metabolic environment for future efforts.

Effects of Moderate-Intensity Physical Training on Skeletal Muscle Substrate Transporters and Metabolic Parameters of Ovariectomized Rats.

A deficit of estrogen is associated with energy substrate imbalance, raising the risk of metabolic diseases. Physical training (PT) is a potent metabolic regulator through oxidation and storage of substrates transported by GLUT4 and FAT CD36 in skeletal muscle. However, little is known about the effects of PT on these carriers in an estrogen-deficit scenario. Thus, the aim of this study was to determine the influence of 12 weeks of PT on metabolic variables and GLUT4 and FAT CD36 expression in the skeletal muscle of animals energetically impaired by ovariectomy (OVX). The trained animals swam 30 min/day, 5 days/week, at 80% of the critical load intensity. Spontaneous physical activity was measured biweekly. After training, FAT CD36 and GLUT4 expressions were quantified by immunofluorescence in the soleus, as well as muscular glycogen and triglyceride of the soleus, gluteus maximus and gastrocnemius. OVX significantly reduced FAT CD36, GLUT4 and spontaneous physical activity (p < 0.01), while PT significantly increased FAT CD36, GLUT4 and spontaneous physical activity (p < 0.01). PT increased soleus glycogen, and OVX decreased muscular triglyceride of gluteus maximus. Therefore, OVX can cause energy disarray through reduction in GLUT4 and FAT CD36 and their muscle substrates and PT prevented these metabolic consequences, masking ovarian estrogen's absence.

Effect of 12-wk Training in Ovariectomised Rats on PGC-1α, NRF-1 and Energy Substrates.

Metabolic diseases are associated with hypoestrogenism owing to their lower energy expenditure and consequent imbalance. Physical training promotes energy expenditure through PGC-1α and NRF-1, which are muscle proteins of the oxidative metabolism. However, the influence of physical training on protein expression in individuals with hypoestrogenism remains uncertain. Thus, the aim of this study is to determine the effect of 12 weeks of moderate-intensity swimming training on the muscle expression of PGC-1α, NRF-1, glycogen and triglyceride in ovariectomised rats. OVX and OVX+TR rats were subjected to ovariectomy. The trained animals swam for 30 minutes, 5 days/week, at 80% of the critical load intensity. Soleus was collected to quantify PGC-1α and NRF-1 expressions, while gastrocnemius and gluteus maximus were collected to measure glycogen and triglyceride. Blood glucose was also evaluated. Whereas ovariectomy decreased PGC-1α expression (p<0.05) without altering NRF-1 (p=0.48), physical training increased PGC-1α (p<0.01) and NRF-1 (p<0.05). Ovariectomy reduced glycogen (p<0.05) and triglyceride (p<0.05), whereas physical training increased glycogen (p<0.05) but did not change triglyceride (p=0.06). Ovariectomy increased blood glucose (p<0.01), while physical training reduced it (p<0.01). In summary, 12 weeks of individualized and moderate-intensity training were capable of preventing muscle metabolic consequences caused by ovariectomy.

Complex networks analysis reinforces centrality hematological role on aerobic-anaerobic performances of the Brazilian Paralympic endurance team after altitude training.

This study investigated the 30-days altitude training (2500 m, LHTH-live and training high) on hematological responses and aerobic-anaerobic performances parameters of high-level Paralympic athletes. Aerobic capacity was assessed by 3000 m run, and anaerobic variables (velocity, force and mechanical power) by a maximal 30-s semi-tethered running test (AO30). These assessments were carried out at low altitude before (PRE) and after LHTH (5-6 and 15-16 days, POST1 and POST2, respectively). During LHTH, hematological analyzes were performed on days 1, 12, 20 and 30. After LHTH, aerobic performance decreased 1.7% in POST1, but showed an amazing increase in POST2 (15.4 s reduction in the 3000 m test, 2.8%). Regarding anaerobic parameters, athletes showed a reduction in velocity, force and power in POST1, but velocity and power returned to their initial conditions in POST2. In addition, all participants had higher hemoglobin (Hb) values at the end of LHTH (30 days), but at POST2 these results were close to those of PRE. The centrality metrics obtained by complex networks (pondered degree, pagerank and betweenness) in the PRE and POST2 scenarios highlighted hemoglobin, hematocrit (Hct) and minimum force, velocity and power, suggesting these variables on the way to increasing endurance performance. The Jaccard's distance metrics showed dissimilarity between the PRE and POST2 graphs, and Hb and Hct as more prominent nodes for all centrality metrics. These results indicate that adaptive process from LHTH was highlighted by the complex networks, which can help understanding the better aerobic performance at low altitude after 16 days in Paralympic athletes.

Acute melatonin administration improves exercise tolerance and the metabolic recovery after exhaustive effort.

The present study investigated the effects of acute melatonin administration on the biomarkers of energy substrates, GLUT4, and FAT/CD36 of skeletal muscle and its performance in rats subjected to exhaustive swimming exercise at an intensity corresponding to the maximal aerobic capacity (tlim). The incremental test was performed to individually determine the exercise intensity prescription and 48 h after, the animals received melatonin (10 mg·kg-1) or vehicles 30 min prior to tlim. Afterwards, the animals were euthanized 1 or 3 h after the exhaustion for blood and muscles storage. The experiment 1 found that melatonin increased the content of glycogen and GLUT4 in skeletal muscles of the animals that were euthanized 1 (p < 0.05; 22.33% and 41.87%) and 3 h (p < 0.05; 37.62% and 57.87%) after the last procedures. In experiment 2, melatonin enhanced the tlim (p = 0.01; 49.42%), the glycogen content (p < 0.05; 40.03%), GLUT4 and FAT/CD36 in exercised skeletal muscles (F = 26.83 and F = 25.28, p < 0.01). In summary, melatonin increased energy substrate availability prior to exercise, improved the exercise tolerance, and accelerated the recovery of muscle energy substrates after the tlim, possibly through GLUT4 and FAT/CD36.

Acute melatonin administration enhances aerobic tolerance: an analysis of biochemical and hematological parameters

Aims: This study is aimed at testing the acute melatonin administration (oral; 6 mg) on aerobic tolerance at cycloergometer and analyzing the consequences on biochemical and hematological parameters. Methods: The maximal aerobic capacity intensity (iMAC) at cycloergometer of eleven male healthy men (24.18±3.92 years-old; 87.07±12.48 kg; 1.82±0.05 m; 26.18±3.63 kg/m2; and 16.28±5.77 % of fat) was individually determined and used to perform a time to exhaustion (tlim) trial of 30 minutes after melatonin or placebo administration. We observed 48-72h interval between tests, performed in a double-blind experiment design. In order to determine hematological and biochemical parameters we collected venous blood samples before and after tlim. Statistical significance was set at 5%. Results The intensity and the lactatemia corresponding to the maximal aerobic capacity were 120.88±18.78 W and 3.32±1.03 mmol.L-1, respectively. The tlim with placebo (33.94±15.26 min, confidence interval = 24.92 - 42.95) was significantly lower than the tlim with melatonin (41.94±17.22 min; CI = 31.76 - 52.12; p = 0.03; 19.06%; effect size = 0.49). All of the 21 analyzed blood physiological variables resulted in no significant variation after tlim when placebo was compared to melatonin, except for total sera cholesterol (lower after exercise with melatonin). Conclusion: Acute melatonin administration enhanced aerobic tolerance at iMAC in 19% at cycloergometer; however, the biochemical and hematological variables assessed were not significantly modulated.(AU)

Metabolic profile and spontaneous physical activity modulation under short-term food restriction in young rats

Abstract AIMS The aim of this study was to investigate the effects of short-term food restriction (6-weeks) on metabolic profile and spontaneous physical activity (SPA) of young male Wistar rats. METHODS Thirty rats had their baseline SPA measured at 21 days-old and were separated into two groups at 28 days-old: Control (CG) and 50% of food restriction (FR). The food restriction protocol lasted six weeks, being the SPA measured weekly by a gravimetric apparatus. At the end of the experiment, biochemical analyses were performed in serum and tissue samples with statistical significance set at 5%. RESULTS FR showed less SPA than CG, as occurred for body mass, water intake, adipose tissue and liver, heart and soleus glycogen, serum glucose, total protein, triglycerides and total cholesterol (P<0.05). CONCLUSION Data set demonstrates that low substrate stores signaled to decrease spontaneous physical activity to save energy.(AU)

Melatonin Has An Ergogenic Effect But Does Not Prevent Inflammation and Damage In Exhaustive Exercise.

It is well documented that exhaustive physical exercise leads to inflammation and skeletal muscle tissue damage. With this in mind, melatonin has been acutely administered before physical exercise; nevertheless, the use of melatonin as an ergogenic agent to prevent tissue inflammation and damage remains uncertain. We evaluated the effects of melatonin on swimming performance, muscle inflammation and damage and several physiological parameters after exhaustive exercise at anaerobic threshold intensity (iLAn) performed during light or dark circadian periods. The iLAn was individually determined and two days later, the animals performed an exhaustive exercise bout at iLAn 30 minutes after melatonin administration. The exercise promoted muscle inflammation and damage, mainly during the dark period, and the exogenous melatonin promoted a high ergogenic effect. The expressive ergogenic effect of melatonin leads to longer periods of muscle contraction, which superimposes a possible melatonin protective effect on the tissue damage and inflammation.

Wide housing space and chronic exercise enhance physical fitness and adipose tissue morphology in rats.

The current cages commonly used in animal experiments can prevent rats from engaging in most forms of natural locomotion behaviors. These animals tend to exhibit sedentary habits. Here, we show that a combination of wide housing space and training exercise helps to reduce white adipose mass and to increase brown adipose mass. Thus, this combination is a useful strategy for truly enhancing the physical fitness of captive rats commonly used in exercise-related interventional studies and to maximize their welfare.

Efeitos do horáiio do dia, luminosidade ambientl e exercício físico sobre parââmetros inflamatórios e de performance em ratos nadadoees / Time of ay, enviironmentluminosity and physical exercise effects on infflammatory and performance parameters of swimming rats

RESUMOO modelo animal é utilizado em inferências de muitos mecanismos fisiológicos ao modelo humano, entretanto, investigações tem negligenciado o completo controle ambiental e cronobiológico. O objetivo deste estudo foi analisar respostas inflamatórias decorrentes do exercício físico realizado até a exaustão em intensidade individualmente determinada na transição aeróbia/anaeróbia em diferentes horários do dia e luminosidades ambientais. Ratos Wistar foram submetidos a dois tipos de luminosidade ambiental durante o período noturno: luminosidade padrão (LP; escuridão total) ou experimental (LE; >600nm; <15lux). Os animais foram avaliados pelo teste de lactato mínimo e então submetidos a um exercício exaustivo nesta intensidade (TE).Todos os procedimentos experimentais foram realizados às 12:00h (período de repouso) ou 20:00h (vigília). TE não sofreu influência do horário ou luminosidade, porém, ratos avaliados sob LP às 20:00h apresentaram menores valores para marcadores inflamatórios, mostrando a importância deste controle em experimentos que envolvam animais noturnos.

ABSTRACTAnimal models are quite used for inferences to Human beings regarding many physiological mechanisms, however, current experiments have been neglected adequate control on environment and chronobiological interferences. The aim of this study was to analyze inflammatory responses owing physical exercise kept until exhaustion at aerobic/anaerobic transition intensity in different times of day and environmental luminosities. Wistar Rats were submitted to a two environmental luminosities during night period: standard luminosity (SL; total darkness) or experimental luminosity (EL; >600nm; <15lux). Animals were submitted to the lactate minimum test and then submitted to an exhaustive exercise at such intensity (TE). Overall experimental procedures were performed at 12:00h or 20:00h. TE were not influenced by time of day or environmental luminosity, nevertheless, were found reduced scores to inflammatory markers to rats assessed under SL at 20:00hs, showing the importance of such control in experiments involving nocturnal animals.

Avaliação da capacidade aeróbia determinada por respostas sanguíneas e ventilatórias em quatro diferentes ergômetros / Assessment of aerobic capacity through blood and ventilatory responses in four different ergometers

O objetivo do presente estudo foi comparar as intensidades do ponto de compensação respiratório (PCR), limiar anaeróbio de concentração fixa (OBLA3,5) e limiar anaeróbio de lactato de aumento abrupto lactacidêmico (LAnLAC) determinadas em diferentes ergômetros. Para isso, onze mesatenistas (19±1 anos) realizaram testes incrementais máximos no cicloergômetro, ergômetro de braço, esteira e em teste específico para o tênis de mesa. Durante esses esforços, foram mensuradas as repostas lactacidêmica e respiratória. Na análise intraergômetro, não foram encontradas diferenças significativas entre o PCR, LAnLAC e OBLA3,5 no ergômetro de braço (63,4±4,8W, 66,9±4,5W e 64,5±6,1W, respectivamente), esteira (11,4±0,4km.h-1, 11,3±0,3km.h-1 e 11,1±0,3km.h-1, respectivamente) e teste específico (40,5±1,8bolas.min-1, 42,6±3,6bolas.min-1 e 42,8±5,6bolas.min-1, respectivamente); apenas no cicloergômetro foi verificado menor valor de OBLA3,5 (131,9±6,6W) em relação ao PCR (149,3±4,9W) e o LAnLAC (149,3±4,7W). No entanto, fortes e significativas correlações foram verificadas no teste específico entre todos esses métodos (r entre 0,83 a 0,95), entre o PCR e OBLA3,5 no ergômetro de braço (r=0,78) e entre OBLA3,5 e LAnLAC na esteira (r=0,76). Desse modo, podemos concluir que o PCR, OBLA3,5 e LAnLAC parecem corresponder ao mesmo fenômeno fisiológico, principalmente, no teste específico para o tênis de mesa.

The objective of the study was to compare intensities of respiratory compensation point (RCP), anaerobic threshold at onset blood lactate accumulation (OBLA3,5), and anaerobic threshold at lactate abrupt increase (AnT LAC) determined in four different ergometers. Hence, eleven table tennis players (19±1 years) performed graded exercise tests on cycle ergometer, arm cranking ergometer, treadmill and specific table tennis test. The respiratory response and lactatemia were measured during the tests. We did not find significant differences among RCP, AnT LAC and OBLA3,5 in arm cranking ergometer (63.4±4.8W, 66.9±4.5W and 64.5±6.1W, respectively), treadmill (11.4±0.4km.h-1, 11.3±0.3km.h-1 and 11.1±0.3km.h-1, respectively), and specific table tennis test (40.5±1.8bolas.min-1, 42.6±3.6bolas.min-1 and 42.8±5.6bolas.min-1, respectively). However, the OBLA3,5 (131.9±6.6W) was significantly lower than RCP (149.3±4.9W) and AnT LAC (149.3±4.7W) in the cycle ergometer. Strong and significant correlation coefficients were found in the specific test for all methods (r range 0.83 to 0.95), in arm cranking ergometer between RCP and OBLA3,5 (r=0.78), and on treadmill running between OBLA3,5 and AnT LAC (r=0.76). Therefore, we conclude that RCP, OBLA3,5 and AnT LAC seem to correspond to the same physiological phenomenon, mostly during specific table tennis test.

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.