Date of Award
1993
Degree Type
Dissertation
Degree Name
Doctor of Philosophy
Abstract
Western blot analyses of SDS-PAGE separated proteins from various hindlimb muscles from non-exercised control animals probed with an HSP 72 monoclonal antibody, demonstrated the constitutive expression of HSP 72 in rat muscles comprised primarily of Type I muscle fibres (soleus), but not in muscles comprised primarily of Type IIB/X fibres (white gastrocnemius-WG). In muscles of mixed fibre type, (plantaris and red gastrocnemius-RG) HSP 72 content was proportional to the percentage of Type I fibres.;Immunolocalization of HSP 72 in cross-sections from the soleus muscle demonstrated that both Type I and Type IIA fibres expressed HSP 72, but Type I fibres expressed a greater amount of HSP 72. In the plantaris muscle, although a few Type IIB fibres in the superficial portion of the muscle demonstrated detectable amounts of HSP 72, the majority of HSP 72 was confined to non-Type IIB fibres in the deep portion of the muscle.;Soleus muscles from rats administered thyroid hormone demonstrated an increase in citrate synthase (CS) activity, the number of Type II fibres, and the number of NADH{dollar}\sb2{dollar}-diaphorase positive fibres, but a decreased HSP 72 content. Immunolocalization of HSP 72 demonstrated no detectable fibre type specific pattern.;Hypertrophied plantaris muscles, demonstrated an increase in the number of Type I fibres and Type I myosin heavy chain (MHC), as well as an increase in HSP 72 content. A strong correlation was established between the proportional increases in HSP 72 content and Type I MHC protein content. Immunolocalization of HSP 72 in cross-sections from hypertrophied plantaris muscles demonstrated HSP 72 to be largely confined to Type I fibres.;Following 4 week sprint or endurance training programmes, HSP 72 content was increased in muscles that constitutively expressed a low amount of HSP 72, such as the plantaris, while muscles that constitutively expressed a high amount of HSP 72, such as the soleus, did not demonstrate an increased HSP 72 content. HSP 72 content was increased to a greater extent following sprint training than endurance training. Four weeks of sprint training elicited significant increases in both CS activity and HSP 72 content in the RG and plantaris muscles, but not in the soleus or WG muscles. (Abstract shortened by UMI.)
Recommended Citation
Locke, Marius, "Hsp 72 In Rat Skeletal Muscle: Fibre Type Differences And Effect Of Exercise" (1993). Digitized Theses. 2178.
https://ir.lib.uwo.ca/digitizedtheses/2178