ABSTRACT

Introduction .................................................................................................................................. 225 Muscular Dystrophy..................................................................................................................... 226 Myotonic Dystrophy .................................................................................................................... 229 Ion Channel Myopathies.............................................................................................................. 230

Myotonia............................................................................................................................. 230 Hyperkalaemic Periodic Paralysis...................................................................................... 231

Malignant Hyperthermia .............................................................................................................. 231 Mitochondrial Myopathies........................................................................................................... 231 Metabolic Myopathies.................................................................................................................. 232 Inflammatory Myopathies ............................................................................................................ 233 Toxic Myopathies......................................................................................................................... 233 Summary ...................................................................................................................................... 233 References .................................................................................................................................... 234

INTRODUCTION

Skeletal muscle accounts for 35 to 40% of body weight, is essential for locomotion and breathing, and is a major modulator of cardiovascular function. Individual muscles are made up of muscle fibers, each of which is a multinucleate cell that can be as long as 10 cm in some human muscles. Abnormalities of skeletal muscle that are directly due to disorders of the muscle are termed myopathies, in contrast to those that are due to disorders of the nerve innervating the muscle (the motor neuron), which are termed neuropathies. Disorders of the motor neuron can produce secondary changes in the muscle; for example acute loss of the motor neuron leads to atrophy of the muscle. Thus, diseases such as amyotrophic lateral sclerosis (motor neuron disease) show abnormalities in the skeletal muscle. This chapter deals with animal models for myopathies, which can arise from a number of causes including both inherited and acquired disease and are summarized in Table 10.1.