Hypobaric-hypoxic exposure and histochemical responses of soleus muscle fibers in the rat.
Hypoxia-acclimatized rats had a higher percentage of fast-twitch oxidative glycolytic fibers and a lower percentage of slow-twitch oxidative fibers in the soleus muscle than age-matched normoxic-rats. However, there was no difference in the fiber type composition of the soleus muscle between hypoxic- and normoxic-male rats after hypoxic-rats were bred at the sea level atmospheric pressure for 5 weeks. Therefore, it is suggested that a higher percentage of fast-twitch oxidative glycolytic fibers in the muscle is found only under hypoxic conditions and is due to an acute response to hypoxia.
Laboratory of Neurochemistry, Faculty of Integrated Human Studies, Kyoto University, Japan.
A
A
Ishihara
K
K
Itho
M
M
Itoh
C
C
Hirofuji
H
H
Hayashi
D000818:Animals; D001274:Atmospheric Pressure; D001835:Body Weight; D005260:Female; D006651:Histocytochemistry; D000860:Hypoxia / Q000473:pathology*; D008297:Male; D009132:Muscles / Q000737:chemistry* / Q000378:metabolism / Q000473:pathology; D051381:Rats; D017207:Rats, Sprague-Dawley; D012727:Sex Characteristics