| Abstrakt: |
Purpose: The purpose of this study was to examine whether repeated heat stress attenuates immobilization-induced skeletal muscle atrophy. Methods: Twelve-week-old male Fischer 344 rats were divided into four groups: control group (CON), heated group (HEAT), immobilized group (IM), and heated and immobilized group (HEAT+IM). Rats in the IM and HEAT+IM groups were immobilized in a plantar flexed position for 7 days. Rats in the HEAT and HEAT+IM groups were exposed to 30 mins of hyperthermia (41°C) on alternating days. After 7 days of immobilization, rats from all groups were anesthetized, and the soleus and plantaris muscles were removed from both hindlimbs. Results: Compared with the CON group, the cross-sectional area (CSA) of the soleus muscle (typical slow-type fiber) and plantaris muscle (typical fast-type fiber) in the IM group was significantly reduced by 26.8% and 27.0%, respectively. The reduction in CSA of the soleus muscle was attenuated by 74.3% in the HEAT+IM group compared with the IM group. However, there is no a significant difference in the CSA of the plantaris muscle between the groups. Conclusion: The results conclude that repeated heat stress may attenuate immobilization-induced skeletal muscle atrophy, although with muscle fiber-type specificity. [ABSTRACT FROM AUTHOR] |
