Changes in the pattern of SDH and PhR staining in fibres of rat masseter muscle following long-term functional stretch.
Histochemical changes in the three basic fibre types of the deep masseter muscle of the rat were studied following functional stretch due to increased vertical dimension of the occlusion. A large number of muscle fibres showed changing histochemical profiles for succinic dehydrogenase (SDH) and phosphorylase (PhR) during degeneration and subsequent regeneration of muscle fibres. On the other hand, a small number of muscle fibres with well defined sarcolemmas presented a normal pattern (i.e. low SDH and high or intermediate PhR activities) during this experiment. The ratio between the three basic fibre types remained unchanged after recovery of the muscle fibres. These results suggest that fast-twitch-oxidative-glycolytic and slow-twitch-oxidative fibres underwent degeneration and regeneration, while almost all the fast-twitch-glycolytic fibres retained normal SDH and PhR staining following functional stretch.
D000818:Animals; D006651:Histocytochemistry; D008297:Male; D008406:Masseter Muscle / Q000166:cytology / Q000201:enzymology*; D008410:Masticatory Muscles / Q000201:enzymology*; D006005:Phosphorylases / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D013194:Staining and Labeling; D013314:Stress, Mechanical; D013385:Succinate Dehydrogenase / Q000378:metabolism*
D013385:Succinate Dehydrogenase; D006005:Phosphorylases