Hot and steady: elevated temperatures do not enhance muscle disuse atrophy during prolonged aestivation in the ectotherm Cyclorana alboguttata

Young, K. M., Cramp, R. L. and Franklin, C. E. (2013) Hot and steady: elevated temperatures do not enhance muscle disuse atrophy during prolonged aestivation in the ectotherm Cyclorana alboguttata. Journal of Morphology, 274 2: 165-174. doi:10.1002/jmor.20080


Author Young, K. M.
Cramp, R. L.
Franklin, C. E.
Title Hot and steady: elevated temperatures do not enhance muscle disuse atrophy during prolonged aestivation in the ectotherm Cyclorana alboguttata
Journal name Journal of Morphology   Check publisher's open access policy
ISSN 0362-2525
1097-4687
Publication date 2013-02
Year available 2012
Sub-type Article (original research)
DOI 10.1002/jmor.20080
Volume 274
Issue 2
Start page 165
End page 174
Total pages 10
Place of publication Hoboken, NJ, United States
Publisher John Wiley & Sons
Collection year 2013
Language eng
Abstract Animals that undergo prolonged dormancy experience minimal muscle disuse atrophy (MDA) compared to animals subjected to artificial immobilisation over shorter timeframes. An association between oxidative stress and MDA suggests that metabolic depression presumably affords dormant animals some protection against muscle disuse. Because aerobic metabolism is temperature sensitive, we proposed that MDA in dormant (aestivating) ectotherms would be enhanced at elevated temperatures. In the green-striped burrowing frog, Cyclorana alboguttata, the thermal sensitivity of skeletal muscle metabolic rate is muscle-specific. We proposed that the degree of atrophy experienced during aestivation would correlate with the thermal sensitivity of muscle metabolic rate such that muscles with a relatively high metabolic rate at high temperatures would experience more disuse atrophy. To test this hypothesis, we examined the effect of temperature and aestivation on the extent of MDA in two functionally different muscles: the M. gastrocnemius (jumping muscle) and M. iliofibularis (non-jumping muscle), in C. alboguttata aestivating at 24 or 30°C for 6 months. We compared a range of morphological parameters from muscle cross-sections stained with succinic dehydrogenase to show that muscle-specific patterns of disuse atrophy were consistent with the relative rates of oxygen consumption of those muscle types. However, despite muscle-specific differences in thermal sensitivity of metabolic rate, aestivation temperature did not influence the extent of atrophy in either muscle. Our results suggest that the muscles of frogs aestivating at high temperatures are defended against additional atrophy ensuring protection of muscle function during long periods of immobilisation.
Keyword Aestivation
Anuran
Atrophy
Muscle disuse
Temperature
Q-Index Code C1
Q-Index Status Confirmed Code
Institutional Status UQ
Additional Notes Article first published online: 20 September 2012.

Document type: Journal Article
Sub-type: Article (original research)
Collections: Official 2013 Collection
School of Biological Sciences Publications
 
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Created: Fri, 01 Feb 2013, 20:53:48 EST by Gail Walter on behalf of School of Biological Sciences