The Muscular Dystrophy group is headed by Dr Stewart Head and their particular interest is in the area of the muscular dystrophies and studying the role of [Ca2+]i in the physiology and pathophysiology of skeletal muscle.
Our group was one of the first to focus on physiological properties of branched fibres (split/malformed) that appear in muscle regenerating from damage, and in dystrophic muscle. Our data have demonstrated an association between the extent of branching and the greater vulnerability to contraction-induced injury in the older fast-twitch dystrophic muscle. Recently, our group has also been involved in research into the role of skeletal muscle Z line cytoskeletal protein-actinin-3, investigating the contractile physiology and [Ca2+]i kinetics of skeletal muscles and fibres from the newly generated homozygous Actn3 knockout mice. The understanding of the consequences for skeletal muscle function of an absence of actinin-3, both in athletes and the general population, is of global importance given the mutation is present in more than 1 billion people worldwide. To date we have analysed the basic contractile properties of actinin-3 deficient muscle demonstrating that in some aspects the mutant fast-twitch muscle behaves like a slow-twitch muscle, relaxing and fatiguing more slowly than its wild-type counterpart and the [Ca2+]i kinetics are similarly slowed compared with wild-type fast fibres. The major techniques utilised include whole muscle force recording to measure contractile properties, muscle fatigue and assess contraction induced damage; single fibre physiology using skinned fibres from skeletal muscle for contractile studies; electrophysiology to analyse ion channel function; and Ca2+ fluorescence microscopy.
Professor Kathryn North M.D., F.R.A.C.P. and Professor Douglas Burrows, Associate Dean, CHW Clinical School, Faculty of Medicine, University of Sydney
- Two shared grants
- One PhD student, Marshall Hogarth
- One postdoctoral researcher, Peter Houweling
- Sharing 1 Goldstar grant
- Current application for NHMRC