Growth hormone plus resistance exercise attenuate structural changes in rat myotendinous junctions resulting from chronic unloading
Myotendinous junctions (MTJs) are specialized sites on the muscle surface where forces generated by myofibrils are transmitted across the sarcolemma to the extracellular matrix. At the ultrastructural level, the interface between the sarcolemma and extracellular matrix is highly folded and interdigi...
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| Format: | Article |
| Language: | English |
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PAGEPress Publications
2013-11-01
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| Series: | European Journal of Histochemistry |
| Subjects: | |
| Online Access: | http://www.ejh.it/index.php/ejh/article/view/2299 |
| _version_ | 1828454323764330496 |
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| author | D. Curzi D. Lattanzi S. Ciuffoli S. Burattini R.E. Grindeland V.R. Edgerton R.R. Roy J.G. Tidball E. Falcieri |
| author_facet | D. Curzi D. Lattanzi S. Ciuffoli S. Burattini R.E. Grindeland V.R. Edgerton R.R. Roy J.G. Tidball E. Falcieri |
| author_sort | D. Curzi |
| collection | DOAJ |
| description | Myotendinous junctions (MTJs) are specialized sites on the muscle surface where forces generated by myofibrils are transmitted across the sarcolemma to the extracellular matrix. At the ultrastructural level, the interface between the sarcolemma and extracellular matrix is highly folded and interdigitated at these junctions. In this study, the effect of exercise and growth hormone (GH) treatments on the changes in MTJ structure that occur during muscle unloading, has been analyzed. Twenty hypophysectomized rats were assigned randomly to one of five groups: ambulatory control, hindlimb unloaded, hindlimb unloaded plus exercise (3 daily bouts of 10 climbs up a ladder with 50% body wt attached to the tail), hindlimb unloaded plus GH (2 daily injections of 1 mg/kg body wt, i.p.), and hindlimb unloaded plus exercise plus GH. MTJs of the plantaris muscle were analyzed by electron microscopy and the contact between muscle and tendon was evaluated using an IL/B ratio, where <em>B</em> is the base and <em>IL</em> is the interface length of MTJ’s digit-like processes. After 10 days of unloading, the mean IL/B ratio was significantly lower in unloaded (3.92), unloaded plus exercise (4.18), and unloaded plus GH (5.25) groups than in the ambulatory control (6.39) group. On the opposite, the mean IL/B ratio in the group treated with both exercise and GH (7.3) was similar to control. These findings indicate that the interaction between exercise and GH treatments attenuates the changes in MTJ structure that result from chronic unloading and thus can be used as a countermeasure to these adaptations. |
| first_indexed | 2024-12-11T00:20:04Z |
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| id | doaj.art-d1c70e7e1446427b97a28cd3e0734866 |
| institution | Directory Open Access Journal |
| issn | 1121-760X 2038-8306 |
| language | English |
| last_indexed | 2024-12-11T00:20:04Z |
| publishDate | 2013-11-01 |
| publisher | PAGEPress Publications |
| record_format | Article |
| series | European Journal of Histochemistry |
| spelling | doaj.art-d1c70e7e1446427b97a28cd3e07348662022-12-22T01:27:48ZengPAGEPress PublicationsEuropean Journal of Histochemistry1121-760X2038-83062013-11-01574e37e3710.4081/ejh.2013.e371367Growth hormone plus resistance exercise attenuate structural changes in rat myotendinous junctions resulting from chronic unloadingD. Curzi0D. Lattanzi1S. Ciuffoli2S. Burattini3R.E. Grindeland4V.R. Edgerton5R.R. Roy6J.G. Tidball7E. Falcieri8Carlo Bo University of UrbinoCarlo Bo University of UrbinoCarlo Bo University of UrbinoCarlo Bo University of UrbinoNASA - Ames Research CenterUniversity of CaliforniaUniversity of CaliforniaUniversity of CaliforniaCarlo Bo University of Urbino CNRMyotendinous junctions (MTJs) are specialized sites on the muscle surface where forces generated by myofibrils are transmitted across the sarcolemma to the extracellular matrix. At the ultrastructural level, the interface between the sarcolemma and extracellular matrix is highly folded and interdigitated at these junctions. In this study, the effect of exercise and growth hormone (GH) treatments on the changes in MTJ structure that occur during muscle unloading, has been analyzed. Twenty hypophysectomized rats were assigned randomly to one of five groups: ambulatory control, hindlimb unloaded, hindlimb unloaded plus exercise (3 daily bouts of 10 climbs up a ladder with 50% body wt attached to the tail), hindlimb unloaded plus GH (2 daily injections of 1 mg/kg body wt, i.p.), and hindlimb unloaded plus exercise plus GH. MTJs of the plantaris muscle were analyzed by electron microscopy and the contact between muscle and tendon was evaluated using an IL/B ratio, where <em>B</em> is the base and <em>IL</em> is the interface length of MTJ’s digit-like processes. After 10 days of unloading, the mean IL/B ratio was significantly lower in unloaded (3.92), unloaded plus exercise (4.18), and unloaded plus GH (5.25) groups than in the ambulatory control (6.39) group. On the opposite, the mean IL/B ratio in the group treated with both exercise and GH (7.3) was similar to control. These findings indicate that the interaction between exercise and GH treatments attenuates the changes in MTJ structure that result from chronic unloading and thus can be used as a countermeasure to these adaptations.http://www.ejh.it/index.php/ejh/article/view/2299Myotendinous junction, ultrastructure, exercise, growth hormone, atrophy, disuse, unloading. |
| spellingShingle | D. Curzi D. Lattanzi S. Ciuffoli S. Burattini R.E. Grindeland V.R. Edgerton R.R. Roy J.G. Tidball E. Falcieri Growth hormone plus resistance exercise attenuate structural changes in rat myotendinous junctions resulting from chronic unloading European Journal of Histochemistry Myotendinous junction, ultrastructure, exercise, growth hormone, atrophy, disuse, unloading. |
| title | Growth hormone plus resistance exercise attenuate structural changes in rat myotendinous junctions resulting from chronic unloading |
| title_full | Growth hormone plus resistance exercise attenuate structural changes in rat myotendinous junctions resulting from chronic unloading |
| title_fullStr | Growth hormone plus resistance exercise attenuate structural changes in rat myotendinous junctions resulting from chronic unloading |
| title_full_unstemmed | Growth hormone plus resistance exercise attenuate structural changes in rat myotendinous junctions resulting from chronic unloading |
| title_short | Growth hormone plus resistance exercise attenuate structural changes in rat myotendinous junctions resulting from chronic unloading |
| title_sort | growth hormone plus resistance exercise attenuate structural changes in rat myotendinous junctions resulting from chronic unloading |
| topic | Myotendinous junction, ultrastructure, exercise, growth hormone, atrophy, disuse, unloading. |
| url | http://www.ejh.it/index.php/ejh/article/view/2299 |
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