Effect of aerobic and anaerobic training on different ergometers in rat muscle and heart tissues / Efeito dos treinamentos aeróbio e anaeróbio em diferentes ergômetros nos tecidos muscular e cardíaco de ratos

ABSTRACT Objective Analyze the effects of aerobic and anaerobic training on different ergometers on muscle and cardiac hypertrophy in rats. Methods The animals were separated into the following groups: Control (C), Aerobic Training in Water (ATW), Resistance Training in Water (RTW), Aerobic Training on Treadmill (ATT), and Resistance Training in Climbing (RTC). All training protocols were carried out for 4 weeks, 3 times/week. The cross-sectional area (CSA) of the gastrocnemius muscle cells and the areas of the cardiomyocytes were measured. Results In the fast-twitch fibers, there was an increase in CSA in the RTW and RTC groups compared to the ATW (p<0.01 and p<0.01) and ATT groups (p<0.01 and p<0.01). In the slow-twitch fibers, the ATW and ATT groups demonstrated a lower CSA compared to the RTW (p=0.03 and p<0.00) and RTC groups (p<0.01 and p<0.01). In the cardiomyocytes, there was an increase in the area of the RTW and RTC groups compared to groups C (p<0.01; p<0.01), ATW (p=0.02; p<0.01), and ATT (p<0.01; p<0.01). Conclusion The anaerobic training effectively promotes hypertrophy in the fast-twitch fibers and the cardiomyocytes. Level of Evidence V; Animal experimental study.

RESUMO Objetivo Analisar os efeitos dos treinamentos aeróbios e anaeróbios em diferentes ergômetros na hipertrofia muscular e cardíaca de ratos. Métodos Os animais foram separados nos grupos controle (C), treinamento aeróbio em natação (ATW), treinamento resistido em meio aquático (RTW), treinamento aeróbio em esteira rolante (ATT) e treinamento resistido em escalada (RTC). Os protocolos de treinamento foram realizados por 4 semanas, 3 x/semana. Foram mensurados a área de secção transversa (CSA) das células do músculo gastrocnêmio e as áreas dos cardiomiócitos. Resultados Nas fibras de contração rápida houve aumento da CSA dos grupos RTW e RTC em relação aos grupos ATW (p<0,01 e p<0,01) e ATT (p<0,01 e p<0,01). Nas fibras de contração lenta os grupos ATW e ATT demonstraram menor CSA comparado aos grupos RTW (p=0,03 e p<0,00) e RTC (p<0,01 e p<0,01). Nos cardiomiócitos houve aumento da área dos grupos RTW e RTC em comparação com os grupos C (p<0,01 e p<0,01), ATW (p=0,02 e p<0,01) e ATT (p<0,01 e p<0,01). Conclusão Os treinamentos anaeróbios promoveram hipertrofia nas fibras de contração rápida e nos cardiomiócitos. Nível de Evidência V; Estudo experimental em animais.

Hormônio do crescimento versus treinamento de força: alterações nas estruturas colágenas, lipídicas e glicídicas / Growth hormone (gh) versus strength training: changes in collagen, lipid and glucidic structures

O objetivo deste estudo foi avaliar o efeito da aplicação de hormônio do crescimento (Growth Hormone - GH) e treinamento de força (TF) na composição do tecido ósseo de ratos Wistar a partir da Espectroscopia Raman. 40 ratos machos foram distribuídos de forma aleatória em quatro grupos: controle (C [n=10]), controle a aplicação de GH (GHC [n=10]), treinamento de força (T [n=10]) e treinamento de força e aplicação de GH (GHT [n=10]). O treinamento foi composto por quatro séries de 10 saltos aquáticos, realizados três vezes por semana, com sobrecarga correspondente a 50% do peso corpóreo e duração de quatro semanas. O GH foi aplicado na dose de 0,2 UI/Kg em cada animal, três vezes por semana e em dias alternados. Ao final do experimento, os animais foram eutanasiados e coletados os fêmures direitos para realização da análise da composição óssea. A espectroscopia Raman (ER) foi utilizada para observar os seguintes compostos a partir de suas respectivas bandas: colágeno e fosfolipídio (1445 cm-1), colesterol (548 cm-1), glicerol (607 cm-1), glicose (913 cm-1), Pico de carboidrato (931 cm-1 ) e prolina (918 cm-1 ). Para a análise estatística, foram realizados os testes de normalidade de Shapiro-Wilk e análise de variâncias ANOVA one-way, seguida pelo pós-teste de Tukey. Os resultados revelaram aumento nas concentrações de colágeno e fosfolipidio, colesterol, glicerol, glicose, pico de carboidrato e prolina em todos os grupos experimentais, associados ou não à realização do ST e/ou aplicação de GH. Porém, somente o grupo T diferiu significativamente do grupo C (p<0,05). Conclui-se que todas intervenções puderam promover ganho no tecido ósseo, porém, somente o grupo T demonstrou diferença significativa nos compostos minerais analisados. (AU)

The objective of this study was to evaluate the effect of the application of growth hormone (GH) and strength training (TF) on the bone tissue composition of Wistar rats using Raman Spectroscopy. 40 male rats were randomly assigned to four groups: control (C [n = 10]), control the application of GH (GHC [n = 10]), strength training (T [n = 10]) and training of strength and application of GH (GHT [n = 10]). The training consisted of four series of 10 water jumps, performed three times a week, with an overload corresponding to 50% of body weight and lasting four weeks. GH was applied at a dose of 0.2 IU / kg to each animal, three times a week and on alternate days. After four weeks, the animals were euthanized and the right femurs were collected to carry out the analysis of the bone composition. Raman spectroscopy (ER) was used to observe the following compounds from their respective bands: collagen and phospholipid (1445 cm-1), cholesterol (548 cm-1), glycerol (607 cm-1), glucose (913 cm-1), Peak carbohydrate (931 cm-1), proline (918 cm-1). For statistical analysis, the Shapiro-Wilk normality tests and ANOVA One-Way analysis of variances were performed, followed by the Tukey post-test. The results revealed an increase in the concentrations of collagen and phospholipid, cholesterol, glycerol, glucose, peak carbohydrate and proline in all experimental groups, associated or not with the performance of ST and / or application of GH. However, only group T differed significantly from group C (p <0.05). It was concluded that all intervention could promote gain in bone tissue, however, only the T group showed a significant difference in the analyzed mineral compounds. (AU)

Effect of high-intensity interval training on the skeletal muscle of spontaneously hypertensive rats

Abstract Aim: This study aimed to evaluate the effect of High-Intensity Interval Training (HIIT) on the skeletal muscle of Spontaneously Hypertensive Rats (SHR). Method: In total, 20 male rats, SHR, 12 months old, were used, distributed into 2 groups: Control Group (C) and Training Group (HIIT). The training lasted approximately 50 minutes/day, 5 days/week, for 8 weeks. Systolic blood pressure (BP) was measured at the beginning and end of the study. Analysis: The medial gastrocnemius muscle was used to measure the smallest fiber diameter, after which the Shapiro-Wilk normality test was performed, followed by the Mann Whitney test to compare the medians and interquartile intervals (IQI) of the muscle fibers and Student t-test for performance. For analysis of BP, Analysis of Variance - ANOVA was used, followed by Tukey's post-test. All procedures adopted a significance value of 5% (p < 0.05). Results: The median values for the variable "smallest diameter" of muscle fibers were 29.48 (IQI: 9.96) µm in the C group and 33.45 (IQI: 9.44) µm in the HIIT group (p < 0.05). Also, the performance was increased in the trained animal group and blood pressure values decreased significantly at the end of the experiment (p < 0.05). Conclusion: The HIIT intensity promoted an increase in the median values of the muscle fibers and performance. Finally, a significant decrease was observed in blood pressure variation values.

Collagen I and III ratios and tenacity of rats muscle injured and treated with platelet-rich plasma / Relaciones de colágeno I y III y tenacidad del músculo de rata lesionado y tratado con plasma rico en plaquetas

SUMMARY: Severe muscle injuries are common in accidents and have a delayed recovery of muscle integrity. In these cases, muscle suture surgery is the standard treatment. However, Platelet Rich Plasma (PRP), has been widely used in orthopedic injuries due to its growth factors. Thus, the objective of the study will be to analyze the association of suture and PRP techniques in the collagen and tenacity of the injured muscle. Were used seventy rats, divided into five groups: control (C), injury control (CI), injury and suture (IS), injury and PRP (IP), injury, suture, and PRP (ISP). Were sectioned approximately 50 % of the width and 100 % of the thickness of the gastrocnemius muscle. The homologous PRP was applied 24h after the injury. On the 7th day after the injury, the animals were euthanized and their muscles subjected to mechanical testing to measure tenacity or collagen analysis to calculate the ratio between type I and III collagen. The results show a significant decrease (p <0.05) in the values of the relationship between collagens in all injured groups (CI, IS, IP, ISP) compared to group C. In injured groups, the tenacity was significantly (p <0.05) reduced compared to the control group, with no observed difference between treatments and injured groups. The amount of collagen in the injured area has increased, but it did not affect the tenacity of the muscles, which was reduced.

RESUMEN: Las lesiones musculares graves son comunes durante los accidentes y la integridad del músculo está sujeta a una larga recuperación. En esos casos la cirugía, para la sutura del músculo, es el tratamiento común, no obstante el plasma rico en plaquetas (PRP) ha sido utilizado recientemente en lesiones ortopédicas, debido a sus factores del crecimiento. El objetivo del estudio fue analizar la asociación de las técnicas de sutura y PRP en la histología y tenacidad de músculo lesionado. Fueron utilizadas 70 ratas distribuidas en cinco grupos: control (C), control lesión (CL), lesión y sutura (LS), lesión y PRP (LPRP), lesión, sutura y PRP (LSPRP). Aproximadamente en la lesión, el 50 % de la longitud y el 100 % del espesor del músculo gastrocnemio fueron seccionados. El PRP homólogo fue aplicado 24 horas después de la lesión. En el 7º día después de la lesión los animales fueron eutanasiados y las muestras fueran sometidas al ensayo mecánico para la medición de la tenacidad y análisis del colágeno, para realizar el cálculo de la relación entre los colágenos I y III. Los resultados demostraron una reducción significativa (p<0,05) en los valores de la relación entre los colágenos en todos los grupos lesionados en relación al grupo C. La tenacidad fue (p<0,05) reducida significativamente en los grupos lesionados en relación al grupo control, sin diferencia entre los tratados. En la lesión muscular hubo disminución de los valores de colágeno, aunque en los tratamientos se observó elevación de la cantidad de colágeno en la área lesionada, esta no tuvo efecto en la tenacidad de los músculos que fue disminuida en la lesión.

Efeito do treinamento concorrente na composição corporal de animais submetidos ao consumo de refrigerante / Effect of concurrent in the body composition of animals submitted to refrigerant consumption

Objetivo ­ Analisar as alterações impostas pelo treinamento concorrente na composição corporal de ratos submetidos ao consumo de refrigerante. Métodos ­ 32 ratos machos da raça Wistar, distribuídos em quatro grupos: Controle (C); Controle Refrigerante (CR); Treinamento Concorrente (TC) e Treinamento Concorrente e Refrigerante (TCR). Os grupos CR e TCR receberam a bebida (0,41 cal/g) do trigésimo ao nonagésimo dia de vida. Foram submetidos a um protocolo de treinamento concorrente, 3x/semana, pelo período de quatro semanas. O protocolo de treino foi composto por 30 minutos de treinamento aeróbio, à 80% do limiar anaeróbio, seguido do treinamento resistido, composto por 4 séries de 10 saltos e sobrecarga de 50% do peso corporal de cada animal. Após 48 horas da última sessão de treinamento, os animais foram submetidos a procedimentos cirúrgicos e mensuraram-se as variáveis de peso corporal, Índice de Massa Corporal (IMC) e Índice de Lee (Lee). Além disso, foi coletado o tecido adiposo epididimal. Resultados ­ Não foram verificadas diferenças significativas entre os índices antropométricos (p>0,05). Houve aumento do peso corporal e gordura visceral nos animais que consumiram refrigerantes. Apenas a variável peso corporal demonstrou diferença estatisticamente significativa (p<0,05). Foi verificado que a glicose sanguínea de jejum se apresentou mais baixa nos grupos que receberam refrigerantes (p<0,05). Conclusão ­ O refrigerante alterou de forma significativa as variáveis de peso corporal, glicose sanguínea de jejum e consumo de água e ração

Objective ­ To analyze the changes imposed by concurrent training on the body composition of rats submitted to the consumption of soda. Methods ­ 32 male Wistar rats, divided into four groups: Control (C); Refrigerant Control (CR); Concurrent Training (TC) and Concurrent Training and Refrigerant (TCR). The CR and TCR groups received the beverage (0.41cal/g) from the 30th to the 90th day of life. They underwent a concurrent training protocol, 3x / week, for a period of four weeks. The training protocol consisted of 30 minutes of aerobic training at 80% of the anaerobic threshold, followed by resistance training consisting of 4 sets of 10 jumps and 50% overload of each animal's body weight. 48 hours after the last training session, the animals underwent surgical procedures and the variables body weight, body mass index (BMI) and Lee index (Lee) were measured. In addition, epididymal adipose tissue was collected. Results ­ No significant differences were found between anthropometric indices (p> 0.05). There was an increase in body weight and visceral fat in animals that consumed soda. Only the body weight variable showed a statistically significant difference (p <0.05). It was found that fasting blood glucose was lower in the groups that received soda (p <0.05). Conclusion ­ The soda significantly changed the variables of body weight, fasting blood glucose and water and feed intake

Effects of different swimming intensities on the bone properties of the tibia and femur of Wistar Rats in which knee rheumatoid arthritis was induced / Efectos de las diferentes intensidades de la natación en las propiedades óseas de la tibia y fémur de Ratas Wistar con artritis reumatoide inducida en rodillas

Rheumatoid arthritis (RA) is a disease triggered by environmental and genetic factors. Research suggests that physical exercise has benefits such as delaying functional disability. In vivo studies using experimental models of arthritis can provide useful information about these benefits. to analyze the effects that different intensities of aquatic physical exercise have on the proprieties of the bones in induced arthritis in knees of Wistar rats. Male Wistar adults rats (n=20) were divided into 5 groups: Group Control Arthritis (GCA) n=4, Group control Placebo (GCP) n=4, Group Low Physical Activity (GB) n=4, Group Moderate Physical Activity (GM) n=4 and Group Intense Physical Activity (GI) n=4. The physical activity groups got an intra-articular injection of Zymosam on the right knee; the GCA received saline solution in the right knee; the GCP was submitted to the stress of the needle. The animals were submitted to aquatic activity for 30 minutes, 4 times a week for 5 weeks, and the intensity of the exercise was determined by a weight placed on their back: GB=1 %, GM=5 %, GI=15 % of their body weight. It was observed that the group GB, and the groups that did not exercise GCA and GCP, gained more weight compared to the group GM. In relation to the bone mineral content of the tibia, there was a decrease in the GM group when compared to the GCP group, whereas in the tibial bone mineral density there was a decrease in the GM group compared to the GCP, GCA, GB. As for the area of the femur, the GI group presented an increase of it compared to the GB and GM groups. It is concluded that the high intensity exercises promote better results in bone properties.

La investigación sugiere que el ejercicio físico tiene beneficios como retrasar la discapacidad funcional de la artritis reumatoide. Los estudios in vivo que utilizan modelos experimentales de artritis pueden proporcionar información útil sobre estos beneficios. Se analizaron los efectos de las intensidades del ejercicio físico acuático sobre las propiedades de los huesos, en la artritis inducida en las rodillas de ratas Wistar. Las ratas Wistar macho adultas (n = 20) se dividieron en 5 grupos: grupo de control artritis (ACG) n = 4, grupo control placebo (CGP) n = 4, grupo de actividad física baja (GB) n = 4, grupo de actividad física moderada (GM) n = 4 y grupo de actividad física intensa (GI) n = 4. Los grupos de actividad física recibieron una inyección intraarticular de Zymosam en la rodilla derecha; el GCA recibió solución salina en la rodilla derecha; el CGP fue sometido a la tensión de una aguja. Los animales fueron sometidos a actividad acuática durante 30 minutos, 4 veces a la semana durante 5 semanas, y la intensidad del ejercicio se determinó mediante un peso colocado sobre su espalda: GB = 1 %, GM = 5 %, GI = 15 % de su peso corporal. Se observó que el grupo GB, y los grupos que no ejercitaron GCA y CGP, ganaron más peso en comparación con el grupo GM. En relación con el contenido mineral óseo de la tibia, hubo una disminución en el grupo GM en comparación con el grupo GCP, mientras que en la densidad mineral del hueso tibial hubo una disminución en el grupo GM en comparación con el GCP, GCA, GB. En cuanto al área del fémur, el grupo GI presentó un aumento en comparación con los grupos GB y GM. En conclusión el ejercicio de alta intensidad promueve mejores resultados en las propiedades óseas.

Effect of growth hormone (GH) and resistance training on the collagen properties of femoral bone tissue / Efecto de la hormona de crecimiento (HC) y el entrenamiento de fuerza en las propiedades colágenas del tejido óseo femoral

The indiscriminate use of anabolic steroids in gyms has been growing in a generalized way, among which, the most common is growth hormone (GH). In the short term GH may potentiate muscle growth, especially when taken in combination with resistance training. However, the effects of this hormone are not yet fully understood in the literature, especially in relation to collagen properties. The objective of this study was to evaluate the effect of the application of growth hormone (GH) and resistance training (RT) on the collagen properties of femoral bone tissue using Raman Spectroscopy. In this study 40 male rats were randomly distributed into four groups (n=10): control (C), control and GH application (GH), resistance training (T), and resistance training and GH application (GHT). The training consisted of four series of 10 water jumps, performed three times a week, with an overload corresponding to 50 % of body weight and duration of four weeks. GH was applied at a dosage of 0.2 IU/Kg (0.067 mg/kg) to each animal, three times a week, every other day. The animals were euthanized and the right femurs were collected for analysis of bone structure. Raman spectroscopy (RS) was used to observe the following compounds from their respective bands: type I collagen (662 cm-1), amide III (1243 cm-1), proteins including type I collagen (1278 cm-1), woven collagen (1322 cm-1), association of collagen, phospholipids, nucleic acid, and phosphate (1330 cm-1), and collagen and protein deformation (1448 cm-1). The results demonstrated an increase in the collagen properties in all analyzed variables, however, the T group presented a statistically significant difference (p<0.05). It is possible to conclude that isolated physical training was shown to be more efficient than when combined with the application of GH to increase the collagen properties of the femoral bone tissue.

El uso indiscriminado de anabolizantes en los gimnasios ha aumentado de forma generalizada, entre éstos la hormona de crecimiento (HC) es una de las más utilizadas, y a corto plazo puede potencializar el crecimiento muscular, principalmente cuando es realizado en combinación con el entrenamiento de fuerza. Sin embargo, los efectos de esta hormona aún no están totalmente esclarecidos en la literatura, especialmente en relación a las propiedades colágenas. El objetivo del estudio fue evaluar el efecto de la aplicación del HC y entrenamiento de fuerza (E) en las propiedades colágenas del tejido óseo femoral a partir de la utilización de la espectroscopía Raman. Se usaron 40 ratas Wistar distribuidos en cuatro grupos (n=10): control (C), control y aplicación del HC (HCC), entrenamiento de fuerza (E) y entrenamiento de fuerza y aplicación del HC (THC). El entrenamiento fue compuesto por cuatro series de 10 saltos acuáticos, realizados tres veces por semana, con sobrecarga correspondiente a 50 % del peso corporal y duración de cuatro semanas. El HC fue aplicado en una dosificación de 0,2 UI/Kg (0,067 mg/kg) en cada animal, tres veces por semana, en días no consecutivos. Los animales fueran eutanasiados y se retiró el fémur derecho para realización del análisis de la estructura ósea. La espectroscopía Raman (ER) fue utilizada para observar los siguientes compuestos a partir de las respectivas bandas: colágeno tipo I (662 cm-1), amida III (1243 cm1), proteínas, incluido colágeno tipo I (1278 cm-1), colágeno retorcido (1322 cm-1), asociación de colágeno, fosfolípidos, ácidos nucleicos y fosfato (1330 cm-1), deformación de colágeno y proteína (1448 cm-1). Hubo aumento en las propiedades colágenas en todas las variables analizadas, sin embargo, solamente el grupo E demostró una diferencia estadísticamente significativa (p<0,05). En conclusión, para el aumento de las propiedades colágenas del tejido óseo femoral, el entrenamiento físico aislado es más eficiente que el entrenamiento combinado con el uso de HC.

Effects of consumption of soft drinks on the muscular morphology of animals submitted to concurrent training / Efecto del consumo de bebidas refrescantes en la morfología muscular de animales sometidos a entrenamiento concurrente

The consumption of industrialized foods and beverages contributes to the increase in body weight and manifestation of diverse illnesses. Among these industrialized products, soft drinks can be mentioned, which when consumed in large quantities can contribute to weight gain and the emergence of chronic non-communicable diseases such as hypertension, diabetes, and obesity. In terms of performance, several training protocols have been used, among which concurrent training is presented as a tool that can aid in the control of body weight and muscle development. Thus, the identification of dietary factors, as well as the use of appropriate training methods, can be essential factors in the increase in physical performance. To study the effects of concurrent training on the skeletal muscles of animals submitted to soft drink consumption. In the present study, 32 male rats were used, of the Wistar breed, in the post-weaning biological phase (30 days). The animals performed a concurrent training protocol. Forty-eight hours after the final training session, the animals were submitted to a surgical procedure to remove samples of gastrocnemius muscle. After preparation of the histological slides, the muscle fibers of the different groups of animals were measured. The median values for the minimum diameter of muscle fibers presented the following values: Control (C): 35.78, Control Soft Drinks (CSD): 36.93, Training (T): 39.12, and Training Soft Drinks (TSD): 37.82. The CSD and TSD groups demonstrated the greatest increase in body mass in relation to the C and T groups. In addition, the groups that performed the concurrent training presented a higher mean of the smallest fiber diameter. It was concluded that the ingestion of soft drinks had a negative effect on the muscular hypertrophy of animals submitted to a concurrent training protocol.

El consumo de alimentos y bebidas industrializadas contribuyen al aumento de peso corporal y manifestación de diversas enfermedades. Entre estos alimentos, se encuentran las bebidas refrescantes, que al ser consumidas en grandes proporciones, pueden contribuir al aumento de peso y a la aparición de enfermedades crónicas, tales como la hipertensión, diabetes y obesidad. En cuanto al desempeño, diversos protocolos han sido utilizados, entre estos, el entrenamiento concurrente que puede ser una forma de ayuda en el control de peso corporal y el desarrollo muscular. Siendo así, la identificación de los factores alimentarios, como también la utilización de los métodos correctos de entrenamiento, pueden ser esenciales en el aumento del desempeño físico. El objetivo del estudio fue investigar los efectos del entrenamiento concurrente en la musculatura esquelética de animales sometidos al consumo de bebidas refrescantes. En la presente investigación fueran utilizadas 32 ratas Wistar. Los animales fueran sometidos a un protocolo de entrenamiento concurrente. Después de 48 horas de la última sesión de entrenamiento, los animales fueran sometidos a un proceso quirúrgico para la remoción de muestras de tejido muscular. Los valores de la media del diámetro de las fibras musculares fueron: Control (C): 35,78; Control y Bebida Refrescante (CBR): 36,93; Entrenamiento (ET): 39,12; y Entrenamiento y Bebida Refrescante (EBR): 37,82. Se observó que los grupos CBR y EBR presentaron mayor aumento de masa corporal en comparación con C y T. Además, los grupos que realizaran el entrenamiento concurrente obtuvieron una mayor media en el diámetro de las fibras. Es posible concluir que el consumo de bebidas refrescantes tiene una influencia negativa en la hipertrofia muscular de animales sometidos a un protocolo de entrenamiento concurrente.

Muscle strength training is better than the use of growth hormone (GH) in bone health of Wistar rats / Entrenamiento de la fuerza muscular es mejor que el uso de la hormona del crecimiento (GH) en salud ósea del ratas Wistar

SUMMARY: The objective of this study was to evaluate the effects of growth hormone (GH) and muscle strength training (ST) on the composition of bone tissue of Wistar rats through Raman spectroscopy. In total, 40 male rats were randomly distributed into four groups: (N = 10) control (C), control with the application of GH (GHC), strength training (T), and strength training with the application of GH (GHT). The training consisted of four series of 10 water jumps, performed three times a week, with an overload corresponding to 50 % of body weight and duration of four weeks. GH was applied at a dose of 0.2 IU / kg in each animal three times a week and every other day. After four weeks, the animals were euthanized and the right femurs collected for analysis of the bone structure. Raman spectroscopy (ER) was used to observe the following compounds from their respective bands: Calcium Carbonate-Triglycerides (fatty acids) 1073 cm-1, Collagen type I 509 cm-1, Bone-DNA Phosphate (Protein) 589 cm-1, Phosphate Phospholipids 1078 cm-1. For the statistical analysis, the Shapiro-Wilk and ANOVA One-Way variance analysis normality tests were performed, followed by the Tukey post-test. The results showed an increase in the concentrations of calcium carbonate-triglycerides (fatty acids), type I collagen, bone phosphate-DNA (protein), and phosphate phospholipids in all experimental groups, with or without ST and/or GH , But only the isolated training group differed significantly from the control group (P <0.05). It was concluded that all treatments could promote bone tissue gain, however, only the T group demonstrated a significant difference in the mineral compounds analyzed.

RESUMEN: El objetivo del estudio fue avaluar el efecto de la aplicación de la hormona del crecimiento (GH) y entrenamiento de la fuerza muscular (EF) en la composición del tejido óseo de ratas Wistar a partir de la espectroscopía Raman. Fueron utilizadas 40 ratas machos distribuidas de forma aleatoria en cuatro grupos (n=10): control (C), control y aplicación de GH (GHC), entrenamiento de la fuerza muscular (EF) y entrenamiento de la fuerza muscular y aplicación del GH (GHE). El entrenamiento fue consistió en cuatro series de 10 saltos acuáticos, realizados tres veces en la semana, con sobrecarga correspondiente a 50 % de la masa corporal y durante cuatro semanas. El GH fue aplicado en la dosificación de 0,2 UI/kg en cada animal, tres veces en la semana y en días alternados. Después de cuatro semanas, los animales fueran eutanasiados y retirados los fémures derechos para un análisis de la estructura ósea. La espectroscopía Raman fue utilizada para observar los siguientes compuestos a partir de las respectivas bandas: Carbonato de Calcio-Triglicéridos (ácidos grasos) 1073 cm-1, Colágeno Tipo I 509 cm-1, Fosfato Óseo-DNA (Proteína) 589 cm1, Fosfato Fosfolípidos 1078 cm-1. Para el análisis estadístico, fueron realizadas las pruebas Shapiro-Wilk y el análisis de variancia ANOVA One-Way, seguida de test post hoc de Tukey. Los resultados revelaran aumento de la concentración de Carbonato de Calcio-Triglicéridos (ácidos grasos), Colágeno Tipo I, Fosfato Óseo- DNA (Proteína), Fosfato Fosfolípidos en todos los grupos experimentales, asociados o no a la realización del EF y/o aplicación del GH. Además, solamente el grupo EF mostró diferencia significativa del grupo C (p<0,05). Es posible concluir que todos los tratamientos mostraran aumentos en el tejido óseo, sin embargo, solamente el grupo T demostró una diferencia significativa en los compuestos minerales analizados.

Effects of concurrent training associated with N-acetylcysteine on bone density of spontaneously hypertensive rats

Abstract Aim: The present study aimed to analyze the effects of N-acetylcysteine supplementation associated with concurrent training on the bone mineral density of spontaneously hypertensive elderly rats. Methods: For the present study, 28 male spontaneously hypertensive rats, six months old, were distributed in the following groups: control (C, n=7); control + N-acetylcysteine (CNAC, n=7); concurrent training (T, n=7); and concurrent training+N-acetylcysteine (TNAC, n=7). The concurrent training was composed of aerobic training on a treadmill and resistance training in the same training session, three times a week. Animals of the NAC groups received a dose equivalent to 120 mg/kg/day orally for eight weeks. The animals in the trained groups underwent training for eight weeks. The animals were evaluated at the beginning and end of the experiment. After euthanasia, the tibias and femurs were submitted to bone densitometry analysis in an X-ray dual emission device. Results: Lower weight variation was observed in the trained animals and a reduction in pressure values in all groups, but without a statistical difference (p> 0.05). The animals in the T and TNAC groups presented a better performance in the physical tests (p <0.05). In relation to bone, the NAC groups demonstrated a decrease in femoral bone density when compared to groups C and T. Finally, all experimental groups demonstrated an increase in tibial bone density, but with no statistical difference (p>0.05). Conclusion: The animals in group T demonstrated better performance in the physical tests. In addition, the NAC caused a reduction in the bone mineral density of the femur.

Adaptations of muscle tissue of rats submitted to aerobic and anaerobic physical training in different ergometer models / Adaptaciones en tejido muscular de ratas sometidas a entrenamiento físico aeróbico y anaeróbico en diferentes modelos de ergómetros

SUMMARY The objective of the present study was to analyze the effects of four different training models, two aerobic and two anaerobic models, in relation to muscular hypertrophy, by means of morphometric analysis of the muscle cells of the soleus muscle and the extensor digitorum longus muscle (EDL). The animals were divided into five groups, control (C), aerobic training in swimming (ATS), resistance training in water (RTW), aerobic training on a treadmill (ATT), and resistance training in climbing (RTC). The aerobic training was performed at 70 % of the anaerobic threshold for 30 minutes, while the RTW was composed of 3 series of 10 jumps, and the RTC 4 series of climbs, both at 80 % of the maximum load. All training protocols were performed for a total period of 4 weeks, 3 times per week. The diameters of the muscle cells were measured by means of histological slides of the EDL and soleus muscles. For the EDL muscle, there was no difference between the ATS and ATT aerobic training models (p = 0.20). However, the RTW presented greater hypertrophy when compared to the RTC (p <0.01). Regarding the soleus muscle, the ATS was responsible for generating greater hypertrophy than the ATT (p <0.01). In addition, the RTC was more efficient at producing hypertrophy than the RTW (p <0.01). In this way, it was concluded that exercise adaptation was according to exercise type, aerobic or anaerobic, and not to the modality used.

RESUMEN El objetivo del estudio fue analizar los efectos de cuatro diferentes modelos de entrenamiento, dos aeróbicos y dos anaeróbicos en la hipertrofia muscular en ratas, a través del análisis morfométrico de las células musculares de los músculos sóleo y extensor largo de los dedos (ELD). Los animales fueran divididos en cinco grupos: control (C), entrenamiento aeróbico en natación (TAN), entrenamiento resistido en medio acuático (TRA), entrenamiento resistido en escalada (TRE) y entrenamiento aeróbico en estera rodante (TRE). Los entrenamientos aeróbicos fueron realizados a 70 % del umbral anaeróbico, durante 30 minutos, en cuanto los TRA fueron realizados por 3 series de 10 saltos y el TRE, 4 series de escaladas, ambos a la intensidad de 80 % de la carga máxima. Todos los protocolos de entrenamientos fueron realizados tres veces a la semana por un período de 4 semanas. Fueron demarcados los diámetros de las células musculares de los músculos ELD y sóleo por medio de láminas histológicas. En el músculo ELD no se pudo observar diferencia entre los modelos de entrenamiento aeróbico TAN y TAE (p=0,20). Además, el TRA demostró mayor hipertrofia comparado al TRE (p<0,01). Con relación al músculo sóleo, el TAN fue responsable de generar mayor hipertrofia respecto al TRA (p<0,01). De este modo es posible concluir que la adaptación depende del tipo de ejercicio, aeróbico o anaeróbico, y no en función de la modalidad utilizada.

Alterations in morphology and aerobic resistance of rats subjected to different physical training protocols / Alteraciones en la morfología y resistencia aeróbica de animales sometidos a diferentes protocolos de entrenamiento

The objective of this study was to investigate the alterations in morphology and aerobic resistance of rats subjected to different physical training protocols. The study consisted of 55 rats of the "Wistar" breed, 100 days of age, over a period of 8 weeks. The animals were randomly distributed between four groups: control (CTLE); neuromuscular anaerobic (TAN); aerobic (TAE) and concurrent training (TCc). After four weeks, some of the animals were euthanized. The body mass index (BMI), Lee index (Lee), epididymal adipose tissue (TecAdp), body weight, and feed efficiency ratio (CoefAlim) were measured. The Anaerobic Threshold was determined by critical workload (7 %, 9 % and 11 % of body weight). TAE and TCc training caused alterations in Lee and BMI, at four and eight weeks respectively (LeeTAE=X:2.86±0.08; X:2.89±0.07 and LeeTCc=X:2.85±0.05; X:3.00±0.09). For the TecAdp, all groups presented a decrease, with the TCc value down after eight weeks (X:1.77±0.32). Finally, TAN training improved the CoefAlim (X:31.57±3.70) after the eight week period and the TCc presented the highest value for Lan (X:7.10±0.80).

El objetivo de este estudio fue investigar las alteraciones en la morfología y la resistencia aeróbica de animales sometidos a diferentes protocolos de entrenamiento. Se analizaron 55 ratas macho "Wistar" de 100 días de edad, durante un período de ocho semanas. Los animales fueron separados aleatoriamente en cuatro grupos: grupo control (CTLE); entrenamiento anaerobio neuromuscular (TAN); entrenamiento aerobio (TAE) y entrenamiento concurrente (TCc). Al término de cuatro semanas, algunos de los animales fueron sacrificados. Se midieron: índice de masa corporal (IMC), índice de Lee (Lee) y tejido adiposo del epidídimo (TecAdp), masa corporal y coeficiente de la eficacia alimentaria (CoefAlim). El umbral anaerobio (Lan) fue determinado por la carga crítica de trabajo (11, 9 y 7 % de la masa corporal). El entrenamiento TAE e TCc provocó alteraciones de Lee e IMC, en los períodos de cuatro y ocho semanas, respectivamente (LeeTAE=X:2,86±0,08; X:2,89±0,07 y LeeTCc=X:2,85±0,05; X:3,00±0,09). En relación a TecAdp, se observó una disminución en todos los grupos. Por último, el entrenamiento TAN mejoró en el período de ocho semanas para la variable CoefAlim (X:31,57±3,70) y el TCc con un valor mayor de Lan (X:7,10±0,80).

Physical exercise after immobilization of skeletal muscle of adult and aged rats / Exercício físico após imobilização de músculo esquelético de ratos adultos e idosos / Ejercicio físico después de la inmovilización del músculo esquelético de ratas adultas y mayores

ABSTRACT Introduction: Immobilization is a treatment technique often used to reduce pain and prevent worsening of the injury. However, it promotes harmful effects on musculoskeletal tissue, resulting in a marked loss of muscle function, which may be aggravated in the elderly. Physical exercise is an important intervention to mitigate these harmful effects. Objective: To analyze possible morphometric changes in the gastrocnemius muscle of rats after immobilization and remobilization with physical exercise. Methods: Fifty-six rats were divided into adult (A) and aged (E) groups and subdivided into adult and aged control (AC and EC), immobilized (AI and EI), free remobilized (AIF and EIF), and remobilized through physical exercise (AIE and EIE). The hind limbs were immobilized with the gastrocnemius muscle in a shortened position for a period of seven days, except for the control group. The exercise protocol consisted of five swimming sessions, once per day (25 minutes/session). The animals were euthanized by administration of an overdose of ketamine hydrochloride plus xylazine hydrochloride, followed by sample collection and preparation of hematoxylin and eosin slides. Measurements of the smallest diameter of 120 muscle fibers of each animal were taken with software NIS-Elements D3.0 - SP7 - Nikon® instruments Inc., NY, USA. Results: There was a significant reduction in the mean fiber diameter in the AI (38.43 µm ± 4.20; p=0.01) and AIF (36.97 µm ± 3.41; p<0.01) groups compared to AC (45.39 µm ± 3.41) and in the EI (42.26 µm ± 4.39; p<0.01), EIF (36.00 µm ± 4.15; p<0.01), and EIE (41.86 µm ± 4.95; p<0.01) groups compared to the EC (51.37 µm ± 3.86) group. The data showed that exercise was able to restore muscle trophism in the adult groups; however, none of the protocols has succeeded in aged rats. Conclusion: Immobilization in the shortened position induced muscle atrophy and physical exercise was effective in restoring muscular trophism only in adult animals. Level of Evidence I; Therapeutic studies - Investigating the Results of Treatment.

RESUMO Introdução: A imobilização é uma técnica de tratamento utilizada frequentemente para redução de dor e prevenção do agravamento da lesão. Entretanto, promove efeitos nocivos no tecido músculo-esquelético, resultando em perda acentuada de função muscular, que pode ser agravada em idosos. O exercício físico constitui intervenção importante para atenuar esses efeitos nocivos. Objetivo: Analisar possíveis alterações morfométricas no músculo gastrocnêmio de ratos após imobilização e remobilização com exercício físico. Métodos: Cinquenta e seis ratos divididos em grupo adulto (A) e grupo idoso (E) e subdivididos em controles adultos e idosos (AC e EC), imobilizado (AI e EI), remobilizado livre (AIF e EIF) e remobilizado por meio de exercício físico (AIE e EIE). Os membros traseiros foram imobilizados com o músculo gastrocnêmio em posição de encurtamento por um período de sete dias, exceto no grupo controle. O protocolo de exercícios foi composto por cinco sessões de natação uma vez por dia (25 minutos/sessão). Os animais foram submetidos à eutanásia por administração de cloridrato de cetamina em dose elevada e cloridrato de xilazina, seguida da coleta da amostra e preparação das lâminas com hematoxilina e eosina. Foram feitas as medidas do menor diâmetro de 120 fibras musculares de cada animal com o software NIS-Elements D3.0 - SP7 - Nikon® instruments Inc.®, NY, EUA. Resultados: Houve redução significante na média do diâmetro das fibras nos grupos AI (38,43 µm ± 4,20; p = 0,01) e AIF (36,97 µm ± 3,41; p < 0,01) com relação ao grupo AC (45,39 µm ± 3,41) e dos grupos EI (42,26 µm ± 4,39; p < 0,01), EIF (36,00 µm ± 4,15; p<0,01) e EIE (41,86 µm ± 4,95; p < 0,01) com relação ao grupo EC (51,37 µm ± 3,86). Os dados mostraram que o exercício foi capaz de restaurar o trofismo muscular nos grupos adultos; entretanto, nenhum dos protocolos teve sucesso nos ratos idosos. Conclusão: A imobilização em posição de encurtamento induziu à atrofia muscular e o exercício físico foi eficaz para restabelecer o trofismo muscular apenas nos animais adultos. Nível de Evidência I; Estudos terapêuticos - Investigação dos resultados do tratamento.

RESUMEN Introducción: La inmovilización es una técnica de tratamiento utilizada frecuentemente para reducir el dolor y prevenir el agravamiento de la lesión. Sin embargo, promueve efectos nocivos en el tejido músculo-esquelético, resultando en una pérdida acentuada de función muscular y puede agravarse en ancianos. El ejercicio físico constituye una intervención importante para atenuar estos efectos nocivos. . Objetivo: Analizar posibles cambios morfométricos en el músculo gastrocnemio de ratas después de la inmovilización y removilización con ejercicio físico. Métodos: Cincuenta y seis ratas divididas en grupo adulto (A) y mayores (E) y subdividas en controles adultos y mayores (AC y EC), inmovilizado (AI y EI), removilizado libre (AIF y EIF) y removilizados con ejercicio físico (AIE y EIE). Las extremidades traseras de los animales fueron inmovilizados con el músculo gastrocnemio en posición de acortamiento por un período de siete días, excepto en el grupo control. El protocolo de ejercicios se compuso de cinco sesiones de natación una vez el día (25 minutos/sesión). Los animales fueron sometidos a la eutanasia por administración de clorhidrato de ketamina en dosis elevada y clorhidrato de xilazina, seguida de la recolección de la muestra y preparación de las láminas con hematoxilina y eosina. Se realizaron las medidas del menor diámetro de 120 fibras musculares en cada animal con el programa NIS-Elements D3.0 - SP7 - Nikon® Instruments Inc. ® , NY, EE.UU. Resultados: Hubo una reducción significativa en la media del diámetro de las fibras en los grupos AI (38,43 µm ± 4,20; p = 0,01) y AIF (36,97 µm ± 3,41; p < 0,01) en comparación con el grupo AC (45,39 µm ± 3,41) y de los grupos EI (42,26 µm ± 4,39; p < 0,01), EIF (36,00 µm ± 4,15; p < 0,01) y EIE (41,86 µm ± 4,95; p < 0,01) con relación al grupo EC (51,37 µm ± 3,86). Los datos mostraron que el ejercicio fue capaz de restaurar el trofismo muscular en los grupos adultos; sin embargo, ninguno de los protocolos tuvo éxito en las ratas mayores. Conclusión: La inmovilización en posición de acortamiento indujo a la atrofia muscular y el ejercicio físico fue eficaz para restablecer el trofismo sólo en los animales adultos. Nivel de Evidencia I; Estudios Terapéuticos - Investigación de los resultados del Tratamento.

Morphometric study of muscle fibers in rats submitted to strength training and growth hormone / Estudio morfométrico de las fibras musculares de ratas sometidos a entrenamiento de la fuerza muscular y hormona del crecimiento

The aim of the present study was to observe the changes in the muscle tissue of rats after application of growth hormone (GH) and performing a strength training protocol (ST). In total, 40 male Wistar rats, 60 days old, were used, divided into four groups: control (C), control and application of GH (GHC), strength training (T), and strength training with the application of GH (GHT). The physical training protocol (PT) was composed of four series of 10 jumps in water, 3x/week, with an overload of 50 % of body weight for four weeks. GH was administered intraperitoneally at a dose of 0.2 IU/Kg to the GHC and GHT groups and saline (0.9 % sodium chloride) to the C and T groups. After four weeks of PT, the animals were euthanized and samples taken from the Soleus muscle. Histological sections were produced with a thickness of 5 mm and stained with hematoxylin-eosin (HE) and nicotinamide adenine dinucleotide tetrazolium reductase (NADH-TR). The markings for determining the measurement of the smallest diameter of muscle fibers (MF) were carried out using the software (AuxioVisionRel 4.8-Carl Zeiss® and NIS-Elements D3.0-SP7-Nikon®). After obtaining the data, the Shapiro-Wilk test for normality was performed and then the nonparametric Kruskal-Wallis with Dunn post-test were used for analysis of MF and the Student t test for the analysis of intragroup body weights. All procedures adopted a 5 % significance value (p <0.05) and were performed using the software SPSS 22.0 for Windows®. It was observed that both the GH and PT were able to generate increased diameter of MF (C:31.81±6.35; GHC:36.88±6.38; T:38.38± 6.94; GHT:36.89±7.16). Moreover, when analyzing the type, a significant increase was found only in the fast twitch MF (C:33.78±7.78; GHC:37.80±6.03; T:38.53±6.94; GHT:37.98±7.65) when compared to the slow twitch (C:25.93±6.66; GHC:26.95±8.03; T:26.24±6.90; GHT:27.20±5.77).

El objetivo de la investigación fue observar las modificaciones en tejido muscular esquelético de ratas después de la aplicación de la hormona del crecimiento (GH) y posterior entrenamiento de fuerza muscular (EFM). Fueran utilizadas 40 ratas Wistar, con 60 días de edad, distribuidas en: control (C), control y aplicación de la hormona del crecimiento (GHC), entrenamiento de fuerza muscular (T), y entrenamiento de fuerza muscular y hormona del crecimiento (GHT). El protocolo de entrenamiento (PT) fue compuesto por cuatro series de diez saltos acuáticos, 3x/semana, con sobrecarga de 50 % del peso corporal, por cuatro semanas. El GH fue aplicado de forma intraperitoneal con una dosis de 0,2UI/kg en grupos GHC y GHT y solución salina (0,9% clorhidrato de sodio) en grupos C y T. Después de cuatro semanas del PT, los animales fueron sacrificados y retirados los músculos sóleos. Se realizaron cortes de 5 µm los que fueron coloreados con Hematoxilina y Eosina (HE), posteriormente fueron sometidos a reacción con nicotinamida adenina dinucleotide tetrazolium reductasa (NADH-TR). Después de la obtención de los datos, fue utilizado la prueba del Shapiro-Wilk para la verificación de la normalidad de los datos y se usó el ensayo de Kruskal-Wallis con pos verificación del Dunn para análisis de las fibras musculares (FM) y prueba t del Student para la análisis del peso corporal entre los grupos. Todos los procedimientos fueron establecidos con valor de la significancia de 5 % (p<0,05) y realizados con el software SPSS 22.0 for Windows®. Fue verificado que tanto lo GH cuanto lo PT fueran capaces de proporcionar el aumento en el diámetro de las FM (C:31.81±6.35; GHC:36.88±6.38; T:38.38±6.94; GHT:36.89±7.16). En relación al tipo de fibras se observó aumento significativo solamente en las FM de contracción rápida (C:33.78±7.78; GHC:37.80±6.03; T:38.53±6.94; GHT:37.98±7.65) cuando se comparó con las FM de contracción lenta (C:25.93±6.66; GHC:26.95±8.03; T:26.24±6.90; GHT:27.20±5.77).

Effects of concurrent training on muscle fibers of Wistar rats submitted to standard and hypercaloric diets / Efecto del entrenamiento concurrente en las fibras musculares de ratas Wistar sometidas a dietas normal e hipercalórica

To analyze the effects of concurrent training (CT) on the muscle fibers of Wistar rats submitted to standard and hypercaloric diets. In total, 40 rats were used, divided into 4 groups: Sedentary Group (GS); Exercise Group (GE), Obese Sedentary Group (OS) and Obese Exercise Group (OE). The animals performed a CT protocol consisting of: muscle strength training and aerobic training, carried out 3 times a week for 45 days. The smallest diameter of muscle fibers (MDF) was analyzed to evaluate muscle hypertrophy. It was observed that the OE group presented a significant decrease in MDF, compared to the OS group (OE=77.41 µm vs. OS=98.58 µm). In addition, the animals that performed CT demonstrated muscle hypertrophy (GE=74.39 µm vs. GS=72.13 µm). In conclusion, the CT with a standard diet promoted an increase in MDF while CT with a hypercaloric diet resulted in a decrease.

El objetivo de este trabajo fue analizar el efecto del entrenamiento concurrente (EC) en las fibras musculares de ratas Wistar sometidas a dietas normal e hipercalórica. Fueron utilizadas 40 ratas Wistar, distribuidas en cuatro grupos de animales: grupo sedentario (GS); grupo ejercicio (GE); grupo obeso sedentario (OS) y grupo obeso ejercicio (OE). Los animales realizaron el protocolo del EC compuesto por entrenamiento de fuerza y aeróbico, tres veces en la semana y por 45 días. La media del menor diámetro (MMD) de las fibras musculares fue medida para verificar la hipertrofia muscular. Fue observado que el grupo OE presentó una significante diminución del MMD comparado al grupo OS (OE=77.41 µm vs. OS=98.58 µm). Además, los animales que fueron sometidos al protocolo del EC demostraron hipertrofia muscular (GE=74.39 µm vs. GS=72.13 µm). Se puede concluir que el protocolo del EC con dieta normal tiene como resultado un aumento del MMD, mientras que el EC con dieta hipercalórica tiene como resultado la diminución del MMD.

Effects of HMB supplementation on body composition of rats / Efectos de la suplementación con HMB sobre la composición corporal en ratas

The aim was to investigate the effects of HMB supplementation on the physical performance and anthropometric parameters of Wistar rats that underwent eight weeks of concurrent training. We used 22 male Wistar rats of approximately 60 days of age, And were divided into four groups: control (C), supplemented control (SC), exercise (E) and supplemented exercise (SE). The training consisted of 30 minutes of swimming with an overload corresponding to 70 % of the anaerobic threshold, a one-minute interval, and four sets of ten jumps in water with a one minute interval between sets and a load of 50 % of body weight. After the tests, the tLIM and tTESTE were obtained and used to evaluate the performance of the animals, and anthropometric indices evaluated. The weight increases during the treatment in the SC animals was significantly higher than the animals in groups C and E. The absolute weight of the muscles, kidney and epididymal fat showed higher values for the SC and SE groups in relation to the others.

Se investigaron los efectos de la suplementación con HMB en el rendimiento físico y los parámetros antropométricos de ratas Wistar sometidas a ocho semanas de entrenamiento concurrente. La muestra consistió en 22 ratas Wistar machos, aproximadamente de 60 días de edad, los que fueron divididos en cuatro grupos: control (C), control suplementado (CS), ejercicio (E) y ejercicio suplementado (ES). El entrenamiento consistió en 30 minutos de natación correspondiente a 70 % de la sobrecarga del umbral anaeróbico, un intervalo de un minuto y cuatro series de diez saltos en el agua con intervalo de un minuto entre series y una carga del 50 % del peso del cuerpo. El tLIM y tTESTE se utilizaron para evaluar el rendimiento de los animales, y los índices antropométricos. El aumento de peso durante el tratamiento CS fue significativamente más alto que las de los grupos C y E. El peso absoluto de los músculos, los riñones y la grasa del epidídimo mostraron valores más altos en los grupos CS y ES en relación con los demás.

Effects of aerobic, anaerobic, and concurrent training on bone mineral density of rats

Abstract A sample of 39 rats were divided into the following groups: baseline (BL); aerobic training (ET4 and ET8); anaerobic training (ST4 and ST8); and concurrent training (CT4 and CT8). The aerobic training was performed by swimming with a load corresponding to 70% of the anaerobic threshold; the anaerobic training was performed by jumping in water with a load corresponding to 50% of body weight; and the concurrent training combined the two protocols. The analysis of BMDwas performed on the tibia of the animals and showed an increase in the density of the ST4, CT4, ET8, ST8, and CT8 groups when compared with both the BL and ET4. Thus, it is concluded that anaerobic exercise was shown to be effective in increasing the BMD of animals afterfour weeks of training; however, aerobic training was only able to raise BMD following eight weeks of training.(AU)

Fractal analysis of skeletal muscle tissue of rats subjected to stretch injury / Análisis fractal de tejido muscular esquelético en ratas sometidas a lesión por estiramiento

The aim of this study was to analyze changes in the skeletal muscle tissue of rats after muscle stretch injury using fractal analysis. Nineteen rats were divided into three groups, Control (n= 5) (C), Lesion two days (n= 7) (L2), and Lesion seven days (n= 7) (L7). Histological slides of the gastrocnemius muscle of the animals were prepared and stained with Hematoxylin and eosin for analysis of the inflammatory process, and picrosirius for the demonstration of collagen. The stained slides were subsequently analyzed using Fractal Dimension (FD). The results showed high FD values of the inflammatory process in the experimental groups L2 and L7 in relation to C (p= 0.000). The analysis of collagen in the picrosirius stained slides showed high FD in the L2 group compared to the L7 (p= 0.0001), with no statistically significant difference among other groups. In summary, the present study demonstrated that fractal analysis was able to identify changes in the inflammatory process in injured skeletal muscle tissue.

El objetivo de la investigación fue observar las modificaciones en tejido muscular esquelético en ratas después de la lesión por estiramiento muscular con análisis fractal. En el estudio se incluyeron 19 ratas, divididas en tres grupos, Control (n= 5) (C), lesión dos días (n= 7) (L2) y lesión siete días (L7). Los cortes histológicos del músculo gastrocnemio fueron coloreados con hematoxilina-eosina para el análisis de la inflamación y picrosirius para la determinación del colágeno. Los cortes histológicos fueron posteriormente analizados por medio de dimensión fractal (FD). Los resultados mostraron valores elevados de FD en proceso inflamatorio en los grupos experimentales L2 y L7, en comparación con grupo C (p= 0,000). El análisis de colágeno mostró mayor FD en grupo L2 comparado con L7 (p= 0,0001), se observó diferencia estadísticamente significativa con los demás. En resumen, esta investigación ha demostrado que el análisis fractal fue capaz de identificar las alteraciones del proceso inflamatorio en tejido muscular esquelético después de la lesión.