Cafeteria Diet Can Affect Bone Microarchitecture in Sedentary and Trained Male Rats.

INTRODUCTION: Poor eating habits and a sedentary lifestyle can impair health. Regular physical activity improves the quality of life and is essential for bone health. Therefore, the present study aimed to evaluate the effects of the cafeteria diet on bone quality of sedentary and exercised rats. METHODS: Sixty young male Wistar rats were divided into six groups (n=10) according to diet composition and activity level, being: SD+CON, standard diet and control; SD+SED, standard diet and sedentary; SD+EX, standard diet and exercised; CD+CON, cafeteria diet and control; CD+SED, cafeteria diet and sedentary; CD+EX, cafeteria diet and exercised. The exercise protocol consisted of 10 ladder-climbing sessions/day, 5 days/week, and the sedentary rats were maintained in individual cages with limited mobility. Body mass and food intake were evaluated weekly. After 10 weeks, the animals were euthanized, and white adipose tissue was collected. The bone structure was evaluated by densitometry, mechanical tests, histomorphometric, and micro-computed tomography analyses. RESULTS: The cafeteria diet increased adipose tissue (p<0.001), decreased bone mineral density (p=0.004), and impaired biomechanical properties (p<0.05) and histomorphometry parameters (p=0.044). The sedentarism decreased bone mineral density (p<0.001) and biomechanical properties (p<0.05), and the exercise did not improve bone properties. CONCLUSION: In this experimental model, it was concluded that the cafeteria diet and a sedentary lifestyle negatively affect bone, and ladder-climbing exercise could not prevent the effects of the unhealthy diet.

A high-fat diet can affect bone healing in growing rats.

A high-fat diet (HFD) can have a negative effect on bone quality in young and old people. Although bone healing in children is normally efficient, there is no evidence that children who have a diet rich in fat have compromised bone fracture regeneration compared with children with recommended dietary fat levels. The purpose of the present study was to evaluate the effects of an HFD on bone healing in growing female rats. Twenty-six postweaning female Wistar rats were divided into two groups (13 animals per group): a standard diet (SD) group and an HFD (with 60% of energy from fat) group. The rats received the assigned diets for 5 weeks, and in the third week they were submitted to an osteotomy procedure of the left tibia. Body mass and feed intake were recorded during the experiment. One day before euthanasia, an insulin tolerance test was performed. After euthanasia, the tibiae were removed and analyzed by densitometry, mechanical testing, histomorphometry, stereology and immunohistochemistry. An HFD caused an adaptive response to maintain energetic balance by decreasing feed intake and causing insulin insensitivity. There was no change in bone mineral density, collagen amount and immunostaining for bone formation, but maximal load and stiffness were decreased in the HFD group. In addition, bone volume had a tendency to be higher in the SD group than in the HFD group. Compared with rats receiving an SD, growing rats receiving an HFD for 5 weeks had similar bone mineral density but altered mechanical properties at the osteotomy defect site.

Effects of latex membrane on guided regeneration of long bones.

Natural latex extracted from Hevea brasiliensis is one of the materials pointed out as potential tissue regenerators. The use of latex-based membranes in bone regeneration might be an alternative to stimulate bone formation. The aim of this study was to evaluate the effects of latex membranes in guided bone regeneration of defects produced in long bones of rats. Sixty rats were equally divided into latex and control groups, and each group was subdivided into two subgroups according to treatment duration of 1 and 4 weeks. Bone defects with 2.5 mm in diameter were surgically made in the left tibia. In the animals of the latex group, a latex membrane was placed over the bone defect. The samples underwent quantitative histological analysis of bone formation and collagen matrix, immunohistochemical analysis of osteogenic protein markers, assessment of bone mechanical properties and bone densitometry, and radiological assessment. The osteocalcin immunostaining data were submitted to the generalized linear model test with two independent factors. For the other data, the multivariate ANOVA with two independent factors was performed. The use of the latex membrane significantly improved (p < 0.005) the volume of newly formed bone, collagen type I matrix, expression of osteopontin, and bone stiffness, both in the early and late stages of regeneration. In conclusion, the latex membrane was able to promote bone regeneration in long bones.

Effects of simvastatin associated with exercise on the mechanical resistance of muscle and bone in rats.

OBJECTIVE: The aim of the present study was to evaluate the influence of simvastatin on mechanical properties of muscle and bone in hypercholesterolemic rats submitted to physical exercise. METHODS: Ten male Wistar rats were submitted to a high-fat diet rich in cholesterol for 90 days. The animals were then divided into two groups: animals treated with physical exercise (EG) and animals treated with physical exercise and simvastatin (ESG). Protocols for physical exercise in water and simvastatin administration were performed for eight weeks. After this period, the animals were euthanized; the left tibia and right gastrocnemius muscle were dissected for mechanical analysis, and the right tibia for densitometry. The data were analyzed using Student's t-test, considering a level of significance of 5%. RESULTS: The comparison of maximum load and stiffness revealed no significant differences between the groups for both the tibia (p = 0.851 and p = 0.259) and the gastrocnemius (p = 0.911 and p = 0.083). The tibia BMD also showed no significant difference between the groups (p = 0.803). CONCLUSION: Simvastatin had no negative effects on mechanical properties in tibia and gastrocnemius of hypercholesterolemic rats submitted to physical exercise.

OBJETIVO: Avaliar a influência da sinvastatina nas propriedades mecânicas de ossos e músculos de ratos hipercolesterolêmicos submetidos a exercício físico. MÉTODOS: Foram usados dez ratos machos da raça Wistar, submetidos a dieta hiperlipídica rica em colesterol por 90 dias. Os animais foram então distribuídos em dois grupos: submetidos a tratamento com exercício físico (GE) e submetidos a tratamento com exercício físico e sinvastatina (GE + S). Foi aplicado um protocolo de exercício físico na água e administração de sinvastatina por oito semanas. Após esse período, os animais foram eutanasiados e dissecados a tíbia esquerda e o músculo gastrocnêmio direito de cada animal para análise mecânica e a tíbia direita para densitometria. Para análise dos dados foi aplicado o teste t de Student, considerou-se nível de significância de 5%. RESULTADOS: A comparação da força máxima e rigidez não revelou diferença significativa entre os grupos tanto para a tíbia (p = 0,851 e p = 0,259) quanto para o músculo gastrocnêmio (p = 0,911 e p = 0,083). A DMO das tíbias também não apresentou diferença significativa entre os grupos (p = 0,803). CONCLUSÃO: A sinvastatina não teve efeitos deletérios nas propriedades mecânicas da tíbia e do músculo gastrocnêmio de ratos hipercolesterolêmicos submetidos a exercício físico aeróbio.

Effects of simvastatin associated with exercise on the mechanical resistance of muscle and bone in rats / Efeitos da sinvastatina associada ao exercício físico na resistência mecânica de músculos e ossos de ratos

ABSTRACT Objective: The aim of the present study was to evaluate the influence of simvastatin on mechanical properties of muscle and bone in hypercholesterolemic rats submitted to physical exercise. Methods: Ten male Wistar rats were submitted to a high-fat diet rich in cholesterol for 90 days. The animals were then divided into two groups: animals treated with physical exercise (EG) and animals treated with physical exercise and simvastatin (ESG). Protocols for physical exercise in water and simvastatin administration were performed for eight weeks. After this period, the animals were euthanized; the left tibia and right gastrocnemius muscle were dissected for mechanical analysis, and the right tibia for densitometry. The data were analyzed using Student's t-test, considering a level of significance of 5%. Results: The comparison of maximum load and stiffness revealed no significant differences between the groups for both the tibia (p = 0.851 and p = 0.259) and the gastrocnemius (p = 0.911 and p = 0.083). The tibia BMD also showed no significant difference between the groups (p = 0.803). Conclusion: Simvastatin had no negative effects on mechanical properties in tibia and gastrocnemius of hypercholesterolemic rats submitted to physical exercise.

RESUMO Objetivo: Avaliar a influência da sinvastatina nas propriedades mecânicas de ossos e músculos de ratos hipercolesterolêmicos submetidos a exercício físico. Métodos: Foram usados dez ratos machos da raça Wistar, submetidos a dieta hiperlipídica rica em colesterol por 90 dias. Os animais foram então distribuídos em dois grupos: submetidos a tratamento com exercício físico (GE) e submetidos a tratamento com exercício físico e sinvastatina (GE+S). Foi aplicado um protocolo de exercício físico na água e administração de sinvastatina por oito semanas. Após esse período, os animais foram eutanasiados e dissecados a tíbia esquerda e o músculo gastrocnêmio direito de cada animal para análise mecânica e a tíbia direita para densitometria. Para análise dos dados foi aplicado o teste t de Student, considerou-se nível de significância de 5%. Resultados: A comparação da força máxima e rigidez não revelou diferença significativa entre os grupos tanto para a tíbia (p = 0,851 e p = 0,259) quanto para o músculo gastrocnêmio (p = 0,911 e p = 0,083). A DMO das tíbias também não apresentou diferença significativa entre os grupos (p = 0,803). Conclusão: A sinvastatina não teve efeitos deletérios nas propriedades mecânicas da tíbia e do músculo gastrocnêmio de ratos hipercolesterolêmicos submetidos a exercício físico aeróbio.

Modalidades Terapêuticas Alteram Limiar de Dor à Pressão de Indivíduos com PontosGatilho Miofasciais / Therapeutic Modalities Change Pressure Pain Threshold in Individuals with Myofascial Trigger Points

A fisioterapia dispõe de vários métodos analgésicos, entre eles a estimulação elétrica nervosa transcutânea (TENS) e o infravermelho terapêutico (IV), porém há dúvidas em relação a qual possua maior efeito e seja mais duradouro. O objetivo do estudo foi analisar o limiar de dor à pressão em indivíduos com ponto gatilho na região de músculo trapézio superior, tratados com recursos eletro e fototerapêuticos. Trinta indivíduos, que apresentavam ponto gatilho ativo na região do trapézio superior, foram randomizados em dois grupos: grupo tratado com TENS (GT) e grupo tratado com infravermelho (GIV). Para avaliar o limiar da dor à pressão foi utilizado um algômetro de pressão, ambos aplicados antes do tratamento, após 30 minutos, 24 e 48 horas; além disso, utilizou-se a escala visual analógica da dor. Para análise estatística foram utilizados testes específicos: teste t não pareado (para comparação entre grupos) e T-student pareado (para comparações intraperíodos), sendo adotado nível de significância de 5%. Observou-se que entre as modalidades terapêuticas estudadas, tanto a TENS quanto o infravermelho apresentaram aumento do limiar de dor à pressão logo após (30 minutos) da aplicação, porém o infravermelho apresentou uma manutenção da analgesia superior a TENS, quando analisado o limiar de dor à pressão.(AU)

Physiotherapy has several analgesic methods, including transcutaneous electrical nerve stimulation (TENS) and therapeutic infrared (IR), but there are doubts as to which has greater effect and is more durable. The aim of this study was to analyze the pressure pain threshold in individuals with trigger points in the upper trapezius muscle region treated with electro and phototherapeutic resources. Thirty (30) individuals with active trigger points in the upper trapezius region, were randomized into two groups: TENS (GT) and infrared (GIV) treated groups. To evaluate the pressure pain threshold, a pressure algometer was used, both applied before the treatment, after 30 minutes, 24 and 48 hours. In addition, the visual analogue pain scale was used. For statistical analysis, specific tests were used: unpaired t-test (for comparison between groups) and paired T-student (for intraperiod comparisons), adopting a significance level of 5%. It was observed that between the therapeutic modalities studied, both the TENS and the infrared presented increase of the pressure pain threshold rigth after (30 minutes) the application; however, the infrared presented a maintenance of the analgesia superior to TENS when analyzing the pressure pain threshold.