[Myofibril breakdown during spreading damage. III. Isolated rat muscles].
Ultrastructural changes have been studied in fast (EDL) and slow (SOL) isolated muscles of rats during Zenker's degeneration (ZD). The general pattern of ZD is similar in both the muscles and proceeds in the same way as in the fast skeletal muscles of amphibians: vacuolation of the T-system and of the sarcoplasmic reticulum occur prior to necrosis, and then contraction knots are formed. The latter detach from the rest of the fiber, and myofibrils degrade into clots of electron dense material. Differences in the development of ZD in this muscle are as follows: vacuolation is more strongly pronounced in EDL, contraction and supercontraction of sarcomeres being more characteristic of SOL. In this ZD region of both the muscles, additional membranes are found in some intracrystal spaces of mitochondria, this phenomenon occuring more frequently in SOL. Selective lysis of the Z-line during ZD has been detected only in single EDL Fibres.
D000818:Animals; D006801:Humans; D008931:Mitochondria, Muscle / Q000648:ultrastructure; D009132:Muscles / Q000503:physiopathology*; D009210:Myofibrils / Q000648:ultrastructure*; D009336:Necrosis; D051381:Rats; D013997:Time Factors; D014617:Vacuoles / Q000648:ultrastructure
Razrushenie miofibrill vo vremia rasprostraniaiushchegosia povrezhdeniia. III. Izolirovannye myshtsy krysy.