ABSTRACT
Myofibers can be dysfunctional without exhibiting elevations in serum muscle enzyme concentrations. Therefore, histopathology, immunohistopathology, and/or ultrastructure of skeletal muscle and nerve biopsies are necessary for the investigation of neuromuscular conditions lacking enzyme changes or for a definitive morphologic diagnosis. This chapter focuses on the basic clinical pathology tests used to diagnose and monitor muscular disorders. Animal models for myopathies provide vital information related to the pathophysiology of muscular diseases, the physiologic effects of exercise and aging on muscle and the efficacy and toxicity of therapeutic modalities. Duchenne's muscular dystrophy is the most common inherited myopathy of children and two good animal models that lack dystrophin are the mdx mouse and the golden retriever muscular dystrophy dog (GRMD also known as CXMD). Myotonic dystrophy is the most common human inherited adult myopathy. An experimental autoimmune myositis produced by injecting homogenates of skeletal muscle and adjuvant into animals is a model of human inflammatory muscle disease.
