Browsing by Subject "Muscle injury"

Now showing 1 - 3 of 3
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    Beneficial effects of cannabinoid receptor type 2 (CB2R) in injured skeletal muscle post-contusion
    (F. Hernández y Juan F. Madrid. Universidad de Murcia: Departamento de Biología Celular e Histología, 2015) Yu, Tianshui; Wang, Xu; Zhao, Rui; Zheng, Jilong; Li, Liqiang; Ma, Wenxiang; Zhang, Shutao Zhang; Guan, Dawei
    The aim of the current study was to investigate the effects of cannabinoid receptor type 2 (CB2R) on the repair process of injured skeletal muscle, which could potentially lay solid foundations as a novel target for curing muscular fibrosis in future. A standardized rat model of skeletal muscle contusion was established, where rats were treated with the CB2R agonist JWH-133 or antagonist AM-630. The in vivo results revealed that CB2R activation with JWH-133 significantly diminished the fibrotic areas, downregulated the mRNA levels of collagen type I/ІІІ and augmented the number of multinucleated regenerating myofibers in the injured zones. The reasons leading to the aforementioned results were directly attributable to decreased mRNA levels of TGF-β1, FN-EIIIA and αSMA, reduced accumulation of myofibroblasts, and concomitantly increased mRNA levels of matrix metalloproteinase-1/2. However, we observed contrasting changes in rats treated with the CB2R antagonist AM-630. These results revealed multiple effects of CB2R in systematically inhibiting fibrotic formation and improving muscle regeneration, alongside its potential for clinical application in patients with skeletal muscle injuries and diseases.
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    Muscle injuries and repair: The role of prostaglandins and inflammation
    (Murcia : F. Hernández, 2003) Prisk, V.; Huard, J.
    Skeletal muscle injuries are a common problem in trauma and orthopaedic surgery. Muscle injuries undergo the healing phases of degeneration, inflammation, regeneration, and fibrosis. Current and experimental therapies to improve muscle regeneration and limit muscle fibrosis include conservative and surgical principles with the adjuvant use of non-steroidal anti-inflammatory drugs (NSAIDs) and growth factor manipulation. NSAIDs appear to have a paradoxical effect on the healing of muscle injuries with early signs of improvement and subsequent late impairment in functional capacity and histology. In vitro and in vivo studies have explored the role of the cyclooxygenases and prostaglandins in the biological processes of healing muscle, including precursor cell activation, myoblast proliferation, myoblast fusion, and muscle protein synthesis. Through use of more specific cyclooxygenase inhibitors, we may be able to better understand the role of inflammation in muscle healing.
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    The use of fluorescent dextrans as a marker of sarcolemmal injury
    (Murcia : F. Hernández, 1994) Carter, G.T.; Kikuchi, N.; Horasek, S.J.; Walsh, S.A.
    We investigated the use of intravenously injected fluorescent dextran molecules (FDx) as a histological marker of sarcolemmal injury. Using fluorescent microscopy, uptake of FDx (average MW 10 kD) was assessed in sections of quadriceps muscles from three models: l ) normal (C57BLlIOSnJ) mice. 2) normal mice run downhill (0, 3, and 7 days post exercise), and 3) non-exercised mdx (dystrophin-deficient) mice. These were compared to serial sections stained with hematoxylin and eosin (H&E). In control muscles. strong fluorescence was seen between fibers (intercellular). Intracellular FDx was observed within cells of the quadriceps from normal mice run downhill at days 0 and 3 post exercise, but not at day 7. On H&E staining. muscle pathology was not observed until day 3, with regeneration by day 7. Intracellular FDx was also observed within mdx muscles, particularly in fibers that appeared pre-necrotic on H&E stained sections. FDx appears to be useful as a histological marker of changes in sarcolemmal integrity associated with muscle injury from eccentric exercise or muscle disease.