Document Detail


Lion (Panthera leo) and caracal (Caracal caracal) type IIx single muscle fibre force and power exceed that of trained humans.
MedLine Citation:
PMID:  23155088     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
This study investigated for the first time maximum force production, shortening velocity (Vmax) and power output in permeabilised single muscle fibres at 12°C from lion, Panthera leo (Linnaeus 1758), and caracal, Caracal caracal (Schreber 1776), and compared the values with those from human cyclists. Additionally, the use and validation of previously frozen tissue for contractile experiments is reported. Only type IIx muscle fibres were identified in the caracal sample, whereas type IIx and only two type I fibres were found in the lion sample. Only pure type I and IIa, and hybrid type IIax fibres were identified in the human samples - there were no pure type IIx fibres. Nevertheless, compared with all the human fibre types, the lion and caracal fibres were smaller (P<0.01) in cross-sectional area (human: 6194±230 μm(2), lion: 3008±151 μm(2), caracal: 2583±221 μm(2)). On average, the felid type IIx fibres produced significantly greater force (191-211 kN m(-2)) and ~3 times more power (29.0-30.3 kN m(-2) fibre lengths s(-1)) than the human IIax fibres (100-150 kN m(-2), 4-11 kN m(-2) fibre lengths s(-1)). Vmax values of the lion type IIx fibres were also higher than those of human type IIax fibres. The findings suggest that the same fibre type may differ substantially between species and potential explanations are discussed.
Authors:
Tertius A Kohn; Timothy D Noakes
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Publication Detail:
Type:  Comparative Study; Journal Article; Research Support, Non-U.S. Gov't     Date:  2012-11-15
Journal Detail:
Title:  The Journal of experimental biology     Volume:  216     ISSN:  1477-9145     ISO Abbreviation:  J. Exp. Biol.     Publication Date:  2013 Mar 
Date Detail:
Created Date:  2013-02-28     Completed Date:  2013-08-12     Revised Date:  2013-09-17    
Medline Journal Info:
Nlm Unique ID:  0243705     Medline TA:  J Exp Biol     Country:  England    
Other Details:
Languages:  eng     Pagination:  960-9     Citation Subset:  IM    
Affiliation:
UCT/MRC Research Unit for Exercise Science and Sports Medicine, Department of Human Biology, PO Box 115, University of Cape Town, Newlands, 7725, South Africa. ta.kohn@uct.ac.za
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MeSH Terms
Descriptor/Qualifier:
Analysis of Variance
Animals
Biomechanics
Body Weights and Measures
Felidae / physiology*
Humans
Lions / physiology*
Muscle Contraction / physiology*
Muscle Fibers, Skeletal / physiology*
Myosin Heavy Chains / genetics,  physiology
Species Specificity
Chemical
Reg. No./Substance:
0/Myosin Heavy Chains
Comments/Corrections

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