Light microscopic study of striated muscle in uremia.

Gastrocnemius muscle biopsies from 28 patients with chronic renal failure were analyzed with a light microscope after staining with Gomori trichrome stain and after histochemical reactions for ATPase and NADH diaphorase. Nineteen (68%) of the biopsies were pathological. Uremic myopathy was seen in eleven (39%) of the biopsies, eight of which were obtained from subjects on regular hemodialysis. Pure myopathic muscle damage was observed in three (11%), both myopathic and neuropathic muscle damage in eight (29%) and pure neuropathic muscle damage in eight (29%) of the biopsies. Fiber type atrophy and hypertrophy of both types were seen. The most common quantitative findings were Type II atrophy, small mean size and type grouping of Type II fibers, and Type I hypertrophy.