Muscle Enzyme Histochemistry

Muscle biopsy is an essential component of the investigation of patients with neuromuscular disorders (and is also often employed in research studies on the effects of exercise on muscle). In order to gain maximum information the SPECIMENS for light microscopy and chemical analysis should NOT BE FIXED but prepared for cryostat sectioning in order to allow for morphological, morphometric, enzyme histochemical and immunocytochemical investigations. Material may also be required for electron microscopy, biochemical or DNA studies. Histochemical enzyme technique on cryostat sections of muscle biopsies provide a better opportunity for defining fiber types and detecting any alteration in muscle fibers. Muscle biopsies are useful in diagnosing denervating disease through myofiber type atrophy or groupings; certain dystropic fibers are deficient in type 2B fibers which is also detectable with enzyme histochemistry procedures.

Hematoxylin and eosin*Muscle fibre architecture, nuclear position and number, degeneration and regeneration, hyaline fibres, fibrosis.
Modified Gomori trichromeNemaline rods and ‘ragged-red’ fibres
Myofibrillar ATPase*Types I, IIa, IIb, IIc
(pH 4.3, 4.6, 10.2)Type grouping
NADH-Tr*Mitochondrial and tubular aggregates
Cytochrome oxidaseMitochondria, enzyme deficiency
Phosphorylase*Enzyme deficiency
Non-specific esterase*Inflammation, lysosomes
PAS*Glycogen, carbohydrate
Oil red O*Lipid