Mitochondrial alterations of skeletal muscle in a heat stress rat model.
The morphological and ultrastructural alterations of skeletal muscle in experimental rats with heat stress were investigated. Fifteen male Sprague-Dawley rats were exposed in a 42 degrees C constant temperature oven, resulting in a heat stress state; ten rats were used as controls. All treated rats had weakness of the 4 limbs associated with increased serum creatine kinase levels (p < 0.01). Soleus muscles were submitted to histological, histochemical, ultrastructural and quantitative-morphometric analysis. The group receiving heat stress showed many ragged-red fibers in Gomori trichrome stain and appeared hyper-reactive in succinate dehydrogenase and cytochrome C oxidase stains. The ultrastructure of ragged-red fibers showed increased mitochondrial aggregation as multiple small nests, which were particularly located in the subsarcolemmal space. The mitochondrial area was significantly increased in heat stress rats (p < 0.001). The consistently increased mitochondrial area and histochemical alterations of mitochondria are early pathological abnormalities in muscles with heat stress and indicate fundamental impairment of energy metabolism.
Hsu
Y D
YD
Department of Neurology, National Defense Medical Center, Taipei, Taiwan, Republic of China.
Chen
S S
SS
Lee
W H
WH
Lin
S Z
SZ
Kao
M C
MC
Tsao
W L
WL
D000818:Animals; D001831:Body Temperature; D003402:Creatine Kinase / Q000097:blood; D006358:Hot Temperature; D008297:Male; D008854:Microscopy, Electron; D008931:Mitochondria, Muscle / Q000502:physiology / Q000648:ultrastructure*; D018482:Muscle, Skeletal / Q000502:physiology / Q000648:ultrastructure*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012016:Reference Values; D013312:Stress, Physiological
D003402:Creatine Kinase