PHYS30005 Lecture Notes - Lecture 28: Masseter Muscle, Glycolysis, Protein Isoform
25 Jul 2018
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Document Summary
Simplified overview of signalling network controlling skeletal muscle mass with hypertrophy and in muscle atrophy. Grouping of fibres by hyosin heavy chain (myhc) composition: 10 myhc species identified in mammalian muscle fibres (could be more, limb muscles: types i, iia, iix (iid) and iib. Fibres as hybrids containing more than one myhc. Fibres exist as either pure (one type of myhc) or as hybrids containing multiple forms e. g. i + Iia, i + iia + iix, iia + iix. Every element of muscle can be altered (not just myhc) sr density, capillary density, mitochondria, fibre diameter, contractile and regulatory proteins, fibre composition. A slow fibre in the mouse not necessarily the same as slow fibre in cat or human. 4 myhcs in limb muscles of smaller mammals. Only 3 myhc in limb muscles of humans. Different techniques (matpase histochemistry, electrophoretic separation/migration of isoforms) also reveal differences between species. Major protein isoforms of thick and thin filaments and sr .
