[Effect of acute physical stress on changes in the ultrastructure of skeletal muscle fibers].
Peculiarities of muscle fibres having various functional profile were investigated in the white rat anterior tibial muscle at an intensive physical work (running in the tread-wheel up to fatigue). Electron microscopy and stereomorphometric methods were applied. In the muscle fibres studied certain ultrastructural changes took place affecting both the energetic and the contractile-myofibrillar apparatuses. In the marginal, and especially in the white fibres an essential dilatation of the sarcoplasmic reticulum (its volumetric part) was observed with decreasing relative volume of mitochondria and a sharp drop in glycogen content. In both types of the fibres (more pronounced in the white ones) intercellular edema, destruction in some mitochondria, focal disturbance in organzation of myofibrils were noted. All these phenomena should be considered as a responsive, or rather, adaptive reaction to the streess situation which urgently mobilizes all the reserves up to their complete exhaustion
D000818:Animals; D006003:Glycogen / Q000378:metabolism; D008297:Male; D008854:Microscopy, Electron; D008931:Mitochondria, Muscle / Q000648:ultrastructure; D009132:Muscles / Q000378:metabolism / Q000648:ultrastructure*; D009210:Myofibrils / Q000648:ultrastructure; D005082:Physical Exertion; D051381:Rats
D006003:Glycogen
Izmeneniia ul'trastruktury skeletnykh myshechnykh volokon pod vliianiem ostrogo fizicheskogo napriazheniia.