Rehabilitation therapy with insulin-like growth factor after acute skeletal muscle injury / Terapia de reabilitação com fator de crescimento semelhante à insulina após lesão muscular esquelética aguda / Terapia de rehabilitación con factor de crecimiento semejante a la insulina después de una lesión aguda del músculo esquelético

ABSTRACT Introduction Skeletal muscle injuries account for 10% to 50% of treadmill sports injuries. Insulin-like growth factor (IGF) is a family of polypeptides with both insulin-like anabolic and growth-promoting effects. Sports play a vital role in the recovery of skeletal muscle injuries. Objective The paper analyzes the ability of insulin-like growth factor 1 (IGF-1) to repair skeletal muscle injury caused by treadmill exercise. Method We injected drugs under the wound after exercise-induced injury in rats. The control group was injected with saline, and the experimental group was injected with an insulin-like growth factor. We conduct histological and electron microscopic structural analysis of rats, Results: After an injury, the experimental group formed a basal lamina protective film earlier than the control group, activated myoblasts, formed myofilaments, formed myotubes, and fused into muscle fibers earlier than the control group. The healing quality was also better. The experimental group was endogenous. The mRNA content of sex IGF-1 and IGF-2 both increased earlier than the control group. Conclusion Local injection of exogenous insulin-like growth factor-1 can stimulate the proliferation of myoblasts and accelerate the post-traumatic repair process of skeletal muscle caused by treadmill sports. Level of evidence II; Therapeutic studies - investigation of treatment results.

RESUMO Introdução As lesões do músculo esquelético representam de 10% a 50% das lesões em esteira esportiva. O fator de crescimento semelhante à insulina (IGF) é uma família de polipeptídeos com efeitos anabólicos e de promoção do crescimento semelhantes à insulina. Os esportes desempenham um papel vital na recuperação de lesões musculares esqueléticas. Objetivo o artigo analisa a capacidade do fator de crescimento semelhante à insulina 1 (IGF-1) em reparar lesões musculares esqueléticas causadas por exercícios em esteira. Método Injetamos drogas sob a ferida após lesão induzida por exercício em ratos. O grupo controle foi injetado com solução salina e o grupo experimental foi injetado com um fator de crescimento semelhante à insulina. Realizamos análises histológicas e microscópicas eletrônicas estruturais de ratos. Resultados Após a lesão, o grupo experimental formou um filme protetor da lâmina basal mais cedo do que o grupo controle, mioblastos ativados, miofilamentos formados, miotubos formados e fundidos em fibras musculares mais cedo do que o grupo controle. A qualidade da cura também foi melhor. O grupo experimental era endógeno. O conteúdo do sexo IGF-1 e IGF-2 mRNA aumentou mais cedo do que no grupo de controle. Conclusão A injeção local de fator de crescimento semelhante à insulina 1 exógeno pode estimular a proliferação de mioblastos e acelerar o processo de reparo muscular esquelético pós-traumático causado por esportes em esteira. Nível de evidência II; Estudos terapêuticos: investigação dos resultados do tratamento.

RESUMEN Introducción Las lesiones del músculo esquelético representan del 10% al 50% de las lesiones deportivas en cinta. El factor de crecimiento semejante a la insulina (IGF) es una familia de polipéptidos con efectos anabólicos y estimulantes del crecimiento semejantes a la insulina. Los deportes juegan un papel vital en la recuperación de las lesiones del músculo esquelético. Objetivo El artículo analiza la capacidad del factor de crecimiento semejante a la insulina 1 (IGF-1) para reparar la lesión del músculo esquelético causada por el ejercicio en cinta. Método inyectamos drogas debajo de la herida después de una lesión inducida por el ejercicio en ratas. Al grupo de control se le inyectó solución salina y al grupo experimental se le inyectó un factor de crecimiento semejante a la insulina. Realizamos análisis estructurales histológicos y microscópicos electrónicos de ratas, Resultados: Después de una lesión, el grupo experimental formó una película protectora de la lámina basal antes que el grupo de control, activó mioblastos, formó miofilamentos, formó miotubos y se fusionó en fibras musculares antes que el grupo de control. La calidad de curación también fue mejor. El grupo experimental fue endógeno. El contenido de ARNm de IGF-1 e IGF-2 de sexo aumentaron antes que en el grupo de control. Conclusión La inyección local de factor de crecimiento semejante a la insulina 1 exógeno puede estimular la proliferación de mioblastos y acelerar el proceso de reparación postraumático del músculo esquelético causado por los deportes en cinta. Nivel de evidencia II; Estudios terapéuticos: investigación de los resultados del tratamiento.

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.

Sarcomere structure: the importance of desmin protein in muscle atrophy / Estructura de sarcómera: la importancia de proteína desmina en atrofia muscular

Knowing the ultrastructure of skeletal muscle is critical to understand how it works under normal situation and the disorders caused by extreme or pathological conditions. Sarcomere is the basic structural unit of striated muscle tissue. An important element of sarcomere architecture are the intermediate filaments, including the desmin protein. Desmin protein contributes to maintenance of cell integrity, efficient transmission of force and mechanochemical signaling within the myocyte. Because of this, desmin protein has constantly been a focus of research that investigates its alterations associated to damage and muscle atrophy under different conditions. The purpose of the following literature review is to describe the basic concepts of muscle ultrastructure, emphasizing the desmin protein role under conditions of muscle disuse atrophy and aging.

Conocer la ultraestructura del músculo esquelético es crítico para entender cómo trabaja bajo situaciones normales y en desórdenes causados por condiciones extremas o patológicas. La sarcómera es la unidad de estructura básica del tejido muscular estriado. Elementos importantes en la arquitectura de la sarcómera son los filamentos intermedios, incluyendo la proteína desmina. La proteína desmina contribuye en mantener la integridad celular, la transmisión eficiente de fuerza y la señalización mecanoquímica dentro del miocito. Debido a lo anterior, la proteína desmina ha sido constante foco de investigación en trabajos que estudian sus alteraciones asociadas a daño y atrofia muscular bajo diferentes condiciones. El propósito de la siguiente revisión de la literatura es describir los conceptos básicos de la ultraestructura muscular, enfatizando en el rol de la proteína desmina bajo condiciones de atrofia muscular por desuso y envejecimiento.

Histological characteristics of botulinum neurotoxin-A on rat skeletal muscles

Botulinum neurotoxins-A [BT-A] are bacterial enzymes that block neurotransmitter release. BT-A is widely used to treat spasticity and dystonias, and also in pharmacocosmetic and in the management of various types of pain. It is therefore important to clarify the histological characteristics involved in muscular tissue postinjection and to reconcile its injection for cosmoses under scope. Fifteen adult albino rats were used in this study and divided into three groups [five rats each]. Group I served as negative control; groups II and III were injected into the right gastrocnemius muscle with BT-A in addition to saline into the left side to serve as positive control. Muscle harvest was examined by LM, EM, and morphometry at 28th day for group II with two rats of group I and at 56th day for group III with three rats of group I. Histological examination revealed neurogenic atrophy, target fiber change, hypertrophied fibers, and dilated aggregates of the sarcotubular system. Neurogenic muscle atrophy following a single BT-A injection should be taken into consideration when repeated BT-A injections into the same muscle are needed

Effect of green tea on aged rat skeletal muscle: a light and electron microscopic study

Age-related sarcopenia represents a powerful risk factor for the loss of independence and physical disability in the elderly. Green tea contains a series of polyphenols called catechins and has been applied for disease prevention and treatment. To determine the effects of the intake of green tea on age-related changes in skeletal muscle. Thirty female albino rats were divided into three equal groups: group I [control adults] included 6-month-old rats, group II [aged]included 18-month-old rats, and group III [green tea treated] included 12-month-old rats that received green tea at a dose of 300mg/kg body weight in 1.5ml distilled water orally daily by a gastric tube for 6 months. Quadriceps muscle was dissected bilaterally and prepared for light and electron microscopical examination. Morphometric and statistical studies of the mean cross-sectional area of myofibers were carried out in the three studied groups. With increasing age, there were focal degeneration and atrophy, and significant decrease in the mean cross-sectional area of myofibers. The connective tissue framework showed increased collagen fiber deposition and deficient reticular fibers. Ultrathin sections showed areas of myofibrillar loss and mitochondria with destroyed cristae. Dense shrunken nuclei of satellite cells were observed. After treatment with green tea, normal-appearing myofibers, except for centrally located nuclei, were observed. The mean cross-sectional area of myofibers increased significantly compared with the aged group. Collagen and reticular fibers were relatively similar to those of the control. Proliferation of satellite cells was observed with restoration of normal myofiber ultrastructure. Good regenerative outcome was observed in aged skeletal muscle after the intake of green tea

Entrapment of the sural nerve on gastrocnemius muscle: histological analysis / Compresión del nervio sural en el músculo gastrocnemio: análisis histológico

Anatomical variations in the formation of the sural nerve are common, although the topographical localization of this nerve is constant. In this report, we describe the histological analysis of anomalous course of the medial sural cutaneous nerve which descended through the gastrocnemius via a tunnel formed within the muscle and fascia. This anatomical curiosity are clinically important when evaluating sensory axonal loss in distal axonal neuropathies since sural nerve mononeuropathy is less likely to occur.

Las variaciones anatómicas en la formación del nervio sural son comunes, aunque la localización topográfica de este nervio es constante. En este reporte se describe el análisis histológico del nervio cutáneo sural medial de curso anómalo, que descendió a través de los músculos gastrognemios en un túnel formado en el músculo y la fascia. Esta curiosidad anatómica es de importancia clínica cuando se evalúa la pérdida sensitiva distal en neuropatías axonales, desde mononeuropatía del nervio sural a otras de menor frecuencia.

Inserción del tendón calcáneo / Insertion of the calcaneus tendon

El tendón calcáneo (TC) en el hombre es el más voluminoso y resistente del cuerpo, constituyéndose por su inserción en un elemento vital en la mecánica articular del pie como también en las numerosas patologías que afectan las regiones talocrural y calcánea. Para el estudio se utilizaron 120 miembros inferiores (60 derechos y 60 izquierdos), de cadáveres formolizados de individuos adultos, de ambos sexos. Se disecó la cara posterior de la pierna desde la línea articular de la rodilla hasta la parte inferior del calcáneo, se retiró el tejido adiposo precalcáneo dejando libre el TC. Se observó que el TC estaba formado, exclusivamente, por la fusión de las aponeurosis de los músculos gastrocnemio y sóleo en 62 casos (51,67 por ciento). El tendón del músculo plantar contribuye a la formación parcial del TC en 38 casos (31,67 por ciento) e integralmente en 20 casos (16,66 por ciento). El ancho del TC a nivel de la terminación del vientre del músculo sóleo fue de 12,88 mm +/- 2,0 en el hombre y de 11,55 mm +/- 1,6 en la mujer y el grosor del TC al mismo nivel de 4,29 mm +/- 0,64 en el hombre y de 4,36 mm +/- 0,64 en la mujer. El ancho del TC a nivel del margen posterosuperior del calcáneo fue de 17,98 mm +/- 1,7 en el hombre y de 17,06 mm +/- 1,53 en la mujer. El grosor del TC al mismo nivel fue de 3,79 mm +/- 0,61 en el hombre y de 3,93 mm /- 0,67 en la mujer. La distancia entre el margen posterosuperior del calcáneo y el inicio de la parte insertada del TC fue de 10,99 mm +/- 2,11 en el hombre y 10,84 +/- 2,71 en la mujer. El largo de la parte insertada del TC fue de 17,78 mm +/- 2,4 en el hombre y de 17,66 mm +/- 4,75 en la mujer. El ancho del TC a nivel de su inserción en el hueso calcáneo fue de 28,77 mm +/- 2,53 en el hombre y de 27,21 mm +/- 2,93 en la mujer. La tendinopatía en la inserción del TC suele ser frecuente requiriendo en algunos casos debridamiento quirúrgico del tendón. Por lo anterior, conocer aspectos morfométricos del TC y de su inserción adq...

In man the calaneous tendon (CT) is the most voluminous and resistent tendon in the body; its insertion is a vital element of the foot joint mechanism as well as in a number of disorders that affect talocrural and calcaneal regions. For the present study 120 lower members (60 right and 60 left) of formolized cadavers, adult subjects of both sexes were used. Posterior surface of the leg was disected from the joint line of the knee to the lower part of the calcaneal removing precalcaneus adipose tissue, exposing the CT. We observed that in 62 cases (51.67 percent) the CT was formed exclusively by fusion of aponeurosis of the gastrocnemius and soleus muscles. In 38 cases (31.67 percent) tendon of the plantar muscle contributes to the partial formation of the CT, and fully integrated in 20 cases (16.66 percent). Width of the CT at the soleus muscle belly end, was 12.88 mm +/- 2.0 in men and 11.55 mm +/- 1.6 women and density at the same level was 4.29 mm +/- 0.64 in men and 4.36 mm +/- 0.64 in women. Width of the CT at the posterosuperior border of the calcaneal was 17.98 mm +/- 17 in men, and 17.06 mm +/- 1.53 in women. CT density at the same level was 3.79 mm +/- 0.61 in men and 3.93 mm +/- 0.67 in women. Distance between posterosuperior border of the calcaneal and starting point of the inserted portion of the CT was 10.99 mm +/- 2.11 in men and 10.84 +/- 2.71 in women. Length of the inserted portion of the CT was 17.78 mm +/- 2.4 in men and 17.66 mm +/- 4.75 in women. Width of the CT at the insertion level in the calcaneus bone was 28.77 mm +/- 2.53 in men and 27.21 mm +/- 2.93 in women. Insertional CT tendinopathy is a chronic condition in some cases requiring surgical debridement of the tendon. Therefore, knowledge of morphological aspects of the CT and its insertion is important at the time of surgical procedures of the talocrural region.

Action of neuwiedase, a metalloproteinase isolated from bothrops neuwiedi venom, on skeletal muscle: an ultrastructural and immunocytochemistry study

The damaging effects of neuwiedase, a non-hemorrhagic snake venom metalloproteinase from P-I class, on gastrocnemius muscle are studied herein. Following neuwiedase injection, ultrastructural alterations were detected early showing disarrangement of skeletal muscle fibers (characterized by discontinuity of Z lines), mitochondrial swelling, and disruption of plasma membrane and basal lamina. Degradation of skeletal muscle and the appearance of an amorphous substance, primarily composed of cellular debris, were noted after 24 hours. The presence of neuwiedase at the injection site (detected by immunocytochemistry) revealed highly specific labeling of myofibril components of damaged myocytes. In addition, proteolysis of muscle proteins assayed through myofibrils extracted from gastrocnemius muscle indicated that neuwiedase provoked degradation of myofibrils, especially myosin. These results suggest that skeletal muscle damage, induced by neuwiedase, is probably due to its proteolytic action on myofibrils, which are responsible for the maintenance of the cellular architecture.

Neurotoxic activity and ultrastructural changes in muscles caused by the brown widow spider Latrodectus geometricus venom / Actividad neurotóxica y cambios ultraestructurales en musculos causados por el veneno de la araña viuda marrón Latrodectus geometricus

Brown widow spider (Latrodectus geometricus) venom (BrWSV) produces few local lesions and intense systemic reactions such as cramps, harsh muscle pains, nausea, vomiting and hypertension. Approximately 16 protein bands under reducing conditions and ~ 14 bands under non-reducing conditions on a 12.5% sodium dodecyl sulfate-polyacrylamide gel electrophoresis were observed. Neurotoxic clinical manifestations were confirmed in vivo, while proteolytic activity was demonstrated on gelatine film. Severe ultrastructural damages in mice skeletal muscles were observed at 3, 6, 12 and 24 h postinjection with at total of 45 µg of venom protein. Infiltration of eosinophils and ruptures of the cellular membranes were observed in the muscles along with swelling of the nuclear cover and interruption of the collagen periodicity. Altered mitochondrias and autophage vacuoles, nuclear indentation and mitochondria without cristae, slight increment of intermyofibrillar and subsarcolemic spaces and myelinic figures formation were also observed. In the capillary, endothelial membrane unfolding into the lumen was noticed; along with myelinic figures compatible with a toxic myopathy. Swollen sarcotubular systems with lysis of membrane, intense mitochondria autophagia and areas without pinocytic vesicles were observed. Swollen mitochondria surrounded by necrotic areas, myofibrillar disorganization and big vacuolas of the sarcotubular system, degenerated mitochondrium with formation of myelinic figure was seen. Glycogenosomes with small particulate, muscle type glycogen was noticed. Autophagic vacuole (autophagolysosomes) and necrotic areas were also noticed. These damages may be due to interactive effects of the multifactorial action of venom components. However, Latrodectus geometricus venom molecules may also be utilized as neuro therapeutic tools, as they affect neuronal activities with high affinity and selectivity. To our knowledge, the present study...

El veneno de la araña viuda marrón (Latrodectus geometricus) produce pocas lesiones locales pero intensas reacciones sistémicas, tales como calambres, dolores musculares severos, nauseas, vómitos e hipertensión arterial. Se observaron ~ 16 bandas de proteina bajo condiciones reducidas y ~14 bandas bajo condiciones no reducidas en electroforesis en geles de poliacrilamida al 12.5%. Las manifestaciones neurotóxicas clínicas fueron confirmadas in vivo, mientras que la actividad proteolítica fue demostrada en una placa de gelatina. Los músculos de ratón se estudiaron durante las 3, 6, 12 y 24 horas después de ser inyectados con 45 µg de proteina de veneno. Los músculos fueron seriamente dañados por este veneno. Se demostró una infiltracción de células eosinofílicas y rupturas de membranas celulares en tejido muscular, al mismo tiempo un fuerte incremento de la membrana nuclear y una interrupción de la periodicidad del colágeno. Se observaron daños en la mitocondria y sin cristaes, vacuolas autofágicas e indentación nuclear. Se notó un aumento de la luz de los espacios intermiofibrilares y subsarcolemicos. En los capilares fue visible un desdoblamiento de la membrana endotelial hacia el lúmen vascular. Del mismo modo, fue visto un hinchamiento del sistema sarcotubular con lisis de las membranas; intensa autofagia de mitocondrias y áreas sin vesículas pinocíticas. Fue además observado, glucogenosomas con glucogeno particulado. Se observaron vacuolas autofágicas (autofagolisosomas) y áreas de necrosis. Estos daños podrían ser atribuídos a los efectos interactivos de una acción multifactorial de los componentes del veneno.

Spontaneous stage differentiation of mouse-virulent Toxoplasma gondii RH parasites in skeletal muscle cells: an ultrastructural evaluation

Although the predilection for Toxoplasma gondii to form cysts in the nervous system and skeletal and heart muscles has been described for more than fifty years, skeletal muscle cells (SkMCs) have not been explored as a host cell type to study the Toxoplasma-host cell interaction and investigate the intracellular development of the parasite. Morphological aspects of the initial events in the Toxoplasma-SkMC interaction were analysed and suggest that there are different processes of protozoan adhesion and invasion and of the subsequent fate of the parasite inside the parasitophorous vacuole (PV). Using scanning electron microscopy,Toxoplasma tachyzoites from the mouse-virulent RH strain were found to be attached to SkMCs by the anterior or posterior region of the body, with or without expansion of the SkMC membrane. This suggests that different types of parasite internalization occurred. Asynchronous multiplication and differentiation of T. gondii were observed. Importantly, intracellular parasites were seen to display high amounts of amylopectin granules in their cytoplasm, indicating that tachyzoites of the RH strain were able to differentiate spontaneously into bradyzoites in SkMCs. This stage conversion occurred in approximately 3 percent of the PVs. This is particularly intriguing as tachyzoites of virulent Toxoplasma strains are not thought to be prone to cyst formation. We discuss whether biological differences in host cells are crucial to Toxoplasma stage conversion and suggest that important questions concerning the host cell type and its relevance in Toxoplasma differentiation are still unanswered.

Histological study of the effect of simvastatin on the skeletal muscle fibers in albino rat and the possible protective effect of coenzyme Q 10

Simvastatin is a lipid lowering agent. It reduces risk of mortality in persons with coronary heart disease. Some patients treated with simvastatin, have developed liver, kidney and skeletal muscle symptoms. Coenzyme Ql0 has a significant antioxidant activity acting as a primary scavenger of free radicals and influences membrane stability in many tissues including skeletal muscle. Was to evaluate the effect of simvastatin drug on the histological structure of skeletal muscle fibers of adult male albino rats and the possible role of coenzyme Q10 [C0Q 10] as a protective agent. 38 adult male albino rats were used and divided into three groups. Group I [control], group II included 10 rats treated with simvastatin for 4 and 12 weeks and group III included 10 rats treated with simvastatin and CoQ 10 orally for 4 and 12 weeks. The gastrocnemius muscle was dissected and prepared for light and electron microscopic study. In rats subjected to high therapeutic dose of simvastatin for 4 and 12 weeks, the gastrocnemius muscle showed variation in size, splitting and focal degeneration of myofibers as well as mononuclear cellular infiltration and increased deposition of collagen fibers in-between muscle fibers. EM revealed mitochondrial degeneration and dilatation of sarcoplasmic reticulum. Mitochondria were markedly accumulated between myofibrils and in subsarcolemmal space. Coadministration of coenzyme Q 10 with simvastatin for 4 and 12 weeks ameliorated most of the above mentioned histological changes in the animals used. Simvastatin drug caused skeletal muscle damage. Coenzyme Q 10 resulted in protection of the skeletal muscle fibers when given concomitantly with simvastatin

Effect of Diabetes Mellitus on the structure of skeletal muscle in adult male albino rats and the protective role of chromium: histological and immunohistochemical study

Diabetes may induce many physiological and biochemical changes in skeletal muscle fibers. These were supposed to be caused by hypoinsulineamia and hyperglyceamia. Chromium is trace element its effect on the body is related to carbohydrate and fat metabolism. Chromium improved the metabolism of skeletal muscle especially in athletes. We evaluate the histological and immunohistochemical changes induced by diabetes in the skeletal muscle and the protective role of chromium. Twenty five adult Sprague-Dawlery male albino rats were used. The rats were divided into two main groups; the control group [10 rats] and the diabetic group [15 rats]. The control group was divided in 2 subgroups 5 animals each. Subgroup Ia served as a control group while subgroup Ib was formed of animals that received oral chromium. Group II in which diabetes was induced using streptozotocin [STZ] was divided into 3 subgroups 5 animals each. Subgroup IIa formed of diabetic rats. Subgroup lib formed of diabetic rats that received insulin. Group IIe formed of diabetic rats that received insulin and chromium. The duration of experiment was 2 months. At the end of experiment, gastrocnemius muscles were dissected out and prepared for H and E stain, electron microscopic study and immunohistochemistry for CD[34] of endothelial cells of capillaries. Skeletal muscle of group IIa showed disruption and discontinuity. Mononuclear cellular infiltrate was detected among skeletal muscle fibers. Ultrathin sections showed damaged myofibrils, swollen irregular mitochondria and absent T tubules within the muscle fibers. Microvasculature of skeletal muscle was decreased as demonstrated by immunostaining for CD[34]. Group IIb showed improvement of skeletal muscle fibers and their microvasculature but not complete as that of the control. In group IIc, there was complete improvement of the skeletal muscle fibers and microvasculature among the muscle fibers. Significant decrease in thickness of muscle fibers in diabetic rats and insulin treated subgroup IIb could be measured. Intake of chromium was found to improve these changes in subgroup IIc. Significant increase in blood glucose was detected in subgroup IIa and was controlled in subgroups IIb and IIc. Diabetes produced marked structural changes in skeletal muscle but these changes could be prevented by intake of chromium in addition to the insulin

Comparative morphological studies on three sarcocystis species in Sohag, Egypt

Samples from the tongue, heart, oesophageal and skeletal muscles were collected from 100 cow and 100 buffalo from Sohag slaughterhouses. Macroscopic examination for sarcocysts was followed by microscopic ones on impression smears and compressed muscles. Histological sections and transmission electron microscope [TEM] studies were done on positive cases. Sarcocystis infection rate of cows were 84%. Two species of Sarcocystis were detected: 1-S. cruzi with a membrane provided with hairlike villar protrusions folded over the surface of the cyst. These protrusions were rod-like, round, oval or irregular in shape and were approximately parallel to the cyst surface. 2-S. hominis characterized by a cyst wall consisting of cylindrical finger-like villar protrusions and having microfilaments. The protrusions were perpendicular on the cyst surface with broad tips and contain microfilaments. Buffaloes' muscle, samples revealed an infection rate of 28%. The macroscopic fusiform-shaped species only was detected [Sarcocystis fusiformis]. The role of cyst wall ultrastructure and thickness were discussed regarding identification and pathogenicity

Comparative ultrastuctural study of the effect of simvastatin [Zocor] and fenofibrate [Lipanthyl] on skeletal muscle of albino rats

This study aimed to detect the effect of Zocor [example of statins] and Lipanthyl [example of fibrates] on the skeletal muscle of male albino rats at the ultrastructural level. For this purpose sixty male albino rats were encountered and were subdivided into five groups. G1 was the control group [20 rats]; and other four groups 10 rats each. G2 received Zocor 0.72 mg/200 mg orally equivalent to the therapeutic dose in adult human and G3 received Lipanthyl 5.4mg/200g orally equivalent to the therapeutic dose in adult human. G4 was the recovery from Zocor intake and G5 was the recovery from Lipanthyl intake. For each group both semithin and ultrathin sections of LS of skeletal muscle were examined. Measurements of the myofibril diameters, average mitochondrial diameters in addition to the counting of the mitochondrial number were done using the image analyzer. The ultrastructural findings in G2 included marked myofibril degeneration in the form of loss and distortion of myofibrils. Mitochondria showed significant decrease in their number and very highly significant increase in their diameters. The nuclei of the muscle fibers appeared either swollen or shrunken, while those of satellite cells appeared shrunken and heterochromatic. G3 demonstrated a mixture of both degenerative and repair processes. The nuclei of satellite cells appeared either heterochromatic or euchromatic. There were focal loss of the myofibrils with very highly significant increase in the mitochondrial number and dilated sarcoplasmic reticulum. G4 showed highly significant decrease in the myofibril diameters compared to the control with the regaining of continuity and organization. G5 demonstrated non significant decrease in the myofibril diameter compared to the control. The present study concluded that Zocor had more damaging effect on skeletal muscle than Lipanthyl. Fortunately these myofibril changes were reversible after the stop of the drugs. It also concluded that the choice of hypolipidemic therapy needs to be based not only on the outcome evidence and cost-effectiveness analysis, but also on safety considerations for the individuals

Effect of exercise on the changes of skeletal muscle fibers due to induced type ii diabetes mellitus light and electron microscopic study

Type II diabetes is one of the most common chronic health problems characterized by insulin resistance. Unfortunately, this resistance is increasing at a very rapid rate due to changing lifestyles. Physical exercise could potentially contribute to prevention or delay of type II diabetes complications. This study focused on role of exercise in controlling skeletal muscle fibers changes due to type II diabetes. Forty adult male albino rats were used and divided into two groups: Group I [control group] included Ia and lb subgroups. Group II [diabetic group] included IIa, IIb subgroups. Type II diabetes was induced in group II by intake of 50% fructose solution for 8 weeks. In subgroups Ib and IIb, rats underwent an exercise swimming program for 4 weeks. In subgroup IIa, blood glucose level was elevated. Some muscle fibers appeared degenerated with homogeneous sarcoplasm and loss of striations. The mitochondrial content was decreased. With electron microscopy, mitochondria appeared pleomorphic and myofilaments were disrupted. In subgroup IIb, exercise greatly attenuated the histological changes seen in subgroup IIa. The skeletal muscle fibers had more or less similar appearance to control group. This work proved that exercise has a great role in controlling skeletal muscle structural changes due to type II diabetes

Effect of the hypothyroidism on the skeletal muscle [Soleus] of the adult male albino rat

The thyroid gland is one of the most important endocrine organs that almost all cells of the body are target sites for its hormones, the thyroid state influences markedly both cardiac and skeletal muscles as has been previously reported by many authors. Concerning the skeletal muscles, the hypothyroidism causes atrophy of the muscle fiber and abnormal accumulation of the glycogen. These findings allow a new field for researchers to study the histological picture of the skeletal muscle and the correlation between muscle/body weight ratios in the hypothyroidism. The present study is planned to throw more light on the structure of the skeletal muscle [soleus] and body weight evaluation in the experimentally induced hypothyroid of adult male albino rats. Twenty healthy adult male albino rats, average weight [170 gms each] were used in this study, the body weight evaluated monthly and the skeletal muscle structure was examined histological by light and electron-microscopes after three months of experimentally hypothyroidism. The body weight of the animals were reduced with statistical significant and the skeletal muscle structure affected by experimentally hypothyroidism, where disorganization of the muscle fibers with clear atrophic changes, reduction of the mitochondria and areas of degeneration with abnormal accumulation of glycogen in the skeletal muscle fibers

Metabolismo mitocondrial y ultraestructura de músculo esquelético de ratón con restricción calórico proteica / Mitochondrial metabolism and ultrastructure of mice's skeletal muscle with caloric proteic restriction

Para estudiar el metabolismo mitocondrial en este trabajo se utilizó el método de permeabilización del tejido muscular mediante saponina, la cual destruye el sarcolema, manteniendo las mitocondrias "in situ". Para crear un modelo de patología mitocondrial se produjo restricción calórico-proteica (RCP) en ratones adultos con un 50 por ciento de la dieta de los ratones alimentados "ad libitum" durante un período de 15 días. Se efectuaron estudios del consumo de oxígeno, relación ADP/O, así como la actividad enzimática de los Complejos I y II de la cadena respiratoria y la determinación de proteínas. Para evaluar el efecto de la saponina sobre el tejido muscular en presencia y ausencia de restricción calórica-proteica se observaron muestras del mismo al microscopio electrónico de transmisión. Los resultados revelaron en los animales una pérdida de peso, disminución en el consumo de oxígeno y de la relación ADP/O en presencia de glutamato y de succinato, por otra parte se obtuvo una disminución evidente de la actividad del Complejo I, sin modificación del Complejo II. Las observaciones obtenidas con el microscopio electrónico demuestran que la RCP en ratas tiene efecto directo sobre el aparato contráctil de las fibras musculares, produciendo desorganización de las estructuras sarcoméricas y reducción importante de los miofilamentos. La saponina, por otra parte afecta todo el sistema de citomembranas.

In this work, the method of permeabilization of muscular tissue with saponin was employed, which destroyed the sarcolemma but maintained the mitochondria "in situ". To create a model of mitochondrial pathology, a caloric-protein restriction (CPR) was produced in adult mice by reducing 50 percent the diet to fed animals for 15 days. Determinations of oxygen consumption, ADP/O ratio, total proteins, as well as enzymatic activities of respiratory chain Complexes I and II were performed. To evaluate the effect of saponin on muscular tissues under normal or CPR conditions, electron microscopy observations were done. Results of the study showed that the animals in CPR group had loss of weight, reduced total proteins, diminished oxygen consumption, lower ADP/O ratio in the presence of glutamate and succinate, and a notable decrement in the activity of Complex I but without modifications of that of Complex II. Electron microscopic observations demonstrates directs effects of CPR over the contractile apparatus of muscle fibers, such as, disorganization of sarcomeric structures and an important reduction of the myofilaments. On the other hand, saponin affected all cytomembranous systems.

The role of ischemic preconditioning at the gracilis muscle of rats in the early phase of reperfusion injury

OBJETIVO: Verificar o papel do precondicionamento isquêmico (PCI) na lesão de isquemia e reperfusão (I/R) do músculo grácil de ratos. MÉTODOS: Trinta ratos Wistar foram distribuídos em três grupos, sendo G-I/R e G-PCI subdivididos em relação ao tempo de isquemia. Produziu-se modelo de quase-amputação do membro posterior por meio de uma incisão, preservando o feixe vascular e o osso femoral, induzindo-se isquemia por 2h e 4h, G-I 2h/R (n=6) e G-I 4h/R (n=6), seguida por 1h de reperfusão. Os Grupos Precondicionados, G-PCI 2h (n=6) e G-PCI 4h (n=6), foram precedidos por 3 ciclos de 5min de isquemia seguidos de 5min de reperfusão, antes da isquemia sustentada. No Grupo Controle, G-C (n=6) realizou-se apenas a abordagem regional. As avaliações morfológicas foram realizadas por meio de Microscopia Óptica (MO) para avaliação da desestruturação miofibrilar, processo inflamatório e estase venosa no tecido do músculo grácil. Foram atribuídos escores semi-quantitativos às variáveis estudadas. RESULTADOS: Houve preservação miofibrilar de 76% em G-I2h/R e 0% em G-I4h/R; G-IPC 2h a preservação foi de 100% e de 67% em G-IPC 4h. A reação inflamatória foi mais acentuada em G-I 4h (100% com inflamação) do que em G-I2h (50%);G-IPC 2h apresentou 82% sem inflamação e G-IPC 4h apresentou 67% sem inflamação. A estase vascular esteve ausente em 17% do G-I 4h e em 33% do G-I 2h; em G-IPC 2h esteve ausente em33% e em G-IPC 4h em 50%. CONCLUSÃO: O PCI mostrou, em uma fase inicial, papel benéfico na lesão de I/R no músculo grácil de ratos, comprovado pela maior preservação das fibras musculares, menor reação inflamatória e menor estase venosa.

Características ultraestructurales del músculo esquelético en pacientes con proteinuria glomerular / Ultrastructure of skeletal muscle in patients with glomerular proteinuria

La proteinuria produce un desbalance importante del metabolismo proteico y lipídico, que favorece la desproteinización del organismo, con grandes repercusiones sistémicas que llegan a afectar hasta el músculo esquelético. En los pacientes con falla renal, usualmente disminuye su masa muscular y se observa debilidad. Los pacientes urémicos terminales, manifiestan atrofia de las fibras musculares tipo II, además de daño miopático primario, causado probablemente por un déficit de la microcirculación. En un afán de dilucidar las posibles alteraciones ultraestructurales precoces presentes en el músculo esquelético de pacientes con glomerulopatías primarias que cursan con proteinuria, se estudiaron 4 pacientes (2 hombres y 2 mujeres) con edades entre 42 y 66 años, pertenecientes al servicio de nefrología del hospital militar ®Dr. Calos Arvelo¼ de Caracas-Venezuela. En todos ellos se realizaron mediciones de enzimas musculares (CK, LDH, AST y ALT), electromiografía de los miembros inferiores y biopsia del músculo cuadriceps femoral. En ninguno de los pacientes se observaron modificaciones en los niveles séricos de las enzimas y a excepción de uno de ellos (caso 4), los registros eletromiográficos fueron normales. A nivel ultraestructural se observó: hinchamiento de los componentes del sistema sarcotubular con presencia de tríadas prominentes, signos de atrofia muscular, núcleos hipercromáticos, glucógeno abundante y glucogenosomas. Algunos capilares intramusculares con la luz parcial o totalmente ocluida, citoplasma endotelial electrón denso, presencia de prolongaciones del citoplasma endotelial hacia la luz del capilar, vesículas pinocíticas y cavéolas. Dichos cambios nos permiten concluir el compromiso estructural del músculo esquelético en pacientes con proteinuria, el cual se hace más evidente a medida que avanza hacia la falla renal y que dicho compromiso tiene una base microvascular que condiciona cambios del metabolismo muscular.

The proteinuria produces an important unbalance of the protein and lipid metabolism that it favors thedesproteinitation of the organism, with big systemic repercussions that end up affecting the skeletal muscle. In the patients with renal failure it usually diminishes their muscular mass and weakness is observed. The terminal uremic patient, manifests atrophy of the fibers muscular type II, besides miopatic primary damage, caused probably for a deficit of the microcirculación. In a desire of elucidating the early ultraestructural alterations present in the skeletal muscle of patient with primary glomerulopaties that curse with proteinuria, four patients were studied (2 men and 2 women) with ages between 42 and 66 years, belonging to the service of nephrology of the military hospital ®Dr. Calos Arvelo¼ of Caracas-Venezuela. In all they were carried out mensurations of muscular enzymes (CK, LDH, AST and ALT), electromiografie of the inferior members and biopsy of the muscle femoral cuadriceps. In none of the patients modifications were observed in the seric levels of the enzymes and to exception of one of them (case 4); the eletromiografic registrations are normal. At ultraestructural level it was observed: swelling of the components of the system sarcotubular with presence of prominent triads, signs of muscular atrophy, hyperchromatic nuclei, abundant glucogen and glucogenosome. Some capillary ones intramuscular with the partial or completely occluded light, electron dense cytoplasm, presence of continuations of the endothelial cytoplasm toward the light of the capillary one, pinocitic vesicles and caveole. This changes allow us to conclude the structural commitment of the skeletal muscle in patient with proteinuria, which becomes more evident as it advances toward the renal failure and that said commitment has a microvascular origin that conditions changes of the muscular metabolism.

Effect of muscular exercise on the skeletal muscles of hypothyroid young albino rats: a light and electron microscopic study

Intact thyroid axis and regular muscular exercise appear to be needed for normal muscular growth. Twenty eight young male albino rats were used in the present study to evaluate the effect of muscular exercise on the skeletal muscles of hypothyroid rats. Specimens were obtained from the gastrocnemius muscles. Animals were divided into 2 major groups. Group I served as a control group. Group II was the experimental group and was subdivided into subgroup IIa which was formed of hypothyroid rats and Subgroup IIb which was formed of hypothyroid rats that were subjected to muscular exercise in the form of swimming for 20 minutes /day for 15 days. Hypothyroidism was induced using carbimazole orally in a dose of 0.05mg/kgm for 15 consecutive days. Hypothyroidism resulted in marked affection of the gastrocnemius muscle. The muscle fibers were seen to be fragmented and contained pyknotic nuclei. There was a statistically highly significant reduction in the mean thickness of the muscle fibers. Glycogen granules were seen to be accumulated inside the muscle fibers. The gastrocnemius myofibrils appeared to be separated by wide gaps that were filled with glycogen. Muscular exercise in the form of swimming resulted in improvement of the muscle fibers of the gastrocnemius muscle. So regular muscular training is recommended in cases of hypothyroidism in young age for normal development of the skeletal muscles