Myofibrillar distribution of succinate dehydrogenase activity and lipid stores differs in skeletal muscle tissue of paraplegic subjects
Journal article
Jonkers, Richard A. M., Dirks, Marlou L., Nabuurs, Christine I. H. C., De Feyter, Henk M., Praet, Stephan F. E., Nicolay, Klaas, Van Loon, Luc J.C. and Prompers, Jeanine Josephine. (2012). Myofibrillar distribution of succinate dehydrogenase activity and lipid stores differs in skeletal muscle tissue of paraplegic subjects. American Journal of Physiology - Endocrinology and Metabolism. 302(3), pp. 365 - 373. https://doi.org/10.1152/ajpendo.00270.2011
Authors | Jonkers, Richard A. M., Dirks, Marlou L., Nabuurs, Christine I. H. C., De Feyter, Henk M., Praet, Stephan F. E., Nicolay, Klaas, Van Loon, Luc J.C. and Prompers, Jeanine Josephine |
---|---|
Abstract | Lack of physical activity has been related to an increased risk of developing insulin resistance. This study aimed to assess the impact of chronic muscle deconditioning on whole body insulin sensitivity, muscle oxidative capacity, and intramyocellular lipid ( IMCL ) content in subjects with paraplegia. Nine subjects with paraplegia and nine able-bodied, lean controls were recruited. An oral glucose tolerance test was performed to assess whole body insulin sensitivity. IMCL content was determined both in vivo and in vitro using 1H-magnetic resonance spectroscopy and fluorescence microscopy, respectively. Muscle biopsy samples were stained for succinate dehydrogenase ( SDH ) activity to measure muscle fiber oxidative capacity. Subcellular distributions of IMCL and SDH activity were determined by defining subsarcolemmal and intermyofibrillar areas on histological samples. SDH activity was 57 ± 14% lower in muscle fibers derived from subjects with paraplegia when compared with controls ( P < 0.05 ), but IMCL content and whole body insulin sensitivity did not differ between groups. In muscle fibers taken from controls, both SDH activity and IMCL content were higher in the subsarcolemmal region than in the intermyofibrillar area. This typical subcellular SDH and IMCL distribution pattern was lost in muscle fibers collected from subjects with paraplegia and had changed toward a more uniform distribution. In conclusion, the lower metabolic demand in deconditioned muscle of subjects with paraplegia results in a significant decline in muscle fiber oxidative capacity and is accompanied by changes in the subcellular distribution patterns of SDH activity and IMCL. However, loss of muscle activity due to paraplegia is not associated with substantial lipid accumulation in skeletal muscle tissue. |
Year | 2012 |
Journal | American Journal of Physiology - Endocrinology and Metabolism |
Journal citation | 302 (3), pp. 365 - 373 |
Publisher | American Physiological Society |
ISSN | 0193-1849 |
Digital Object Identifier (DOI) | https://doi.org/10.1152/ajpendo.00270.2011 |
Scopus EID | 2-s2.0-84856157224 |
Page range | 365 - 373 |
Research Group | Mary MacKillop Institute for Health Research |
Publisher's version | File Access Level Controlled |
Place of publication | United States |
https://acuresearchbank.acu.edu.au/item/86878/myofibrillar-distribution-of-succinate-dehydrogenase-activity-and-lipid-stores-differs-in-skeletal-muscle-tissue-of-paraplegic-subjects
Restricted files
Publisher's version
57
total views0
total downloads1
views this month0
downloads this month