Abstract

This study was designed to investigate regional histochemical fiber composition of the rat skeletal muscle. The stains for sections of the Extensor Digitorum Longus muscle are H&E, trichrome, PAS, SDH and myosin-ATPase. Regional proportions of the fiber types were classified along the superficial to deep and medial to lateral axis. The results obtained are as follows. 1) Distribution of three fiber types(S, I and W fibers) classified by periodic acid Schiff reaction showed little or no difference. 2) Extensor Digitorum Longus muscle was composed of three fiber types (Type I, IIA and IIB fibers) which can be differentiated by staining for myosin-ATPase and SDH. Type IIA fibers were increased in the deep and medial area. Type IIB and I fibers were abundant in the superficial and lateral area.