Skeletal Muscle mRNA Response to Hypobaric and Normobaric Hypoxia After Exercise
Advisor Information
Dustin Slivka
Location
Dr. C.C. and Mabel L. Criss Library
Presentation Type
Poster
Start Date
2-3-2018 9:00 AM
End Date
2-3-2018 10:15 AM
Abstract
Environmental stimuli such as temperature and hypoxia can influence cellular signaling in the skeletal muscle. Previously we have reported no changes in gene expression related to mitochondrial development with acute exposure to normobaric hypoxia. However, exposure to hypobaric hypoxia may elicit different physiological responses. Purpose: To determine the effects of recovery in hypobaric hypoxia (HH), normobaric hypoxia (NH), and normobaric normoxia (NN) after exercise on gene expression related to mitochondrial biogenesis, myogenesis, and proteolysis. Methods: Recreationally trained participants (8 male, 7 female) each completed three trials of 1-h cycling at 70% of Wmax. Following exercise, participants sat in an environmentally controlled chamber for a 4-h recovery period in NN (975 m), NH (4,420 m), or HH (4,420 m) environmental conditions. Muscle biopsies were taken from the vastus lateralis pre-exercise and after a 4-h environmental exposure period. Samples were analyzed using qRT-PCR. Results: SpO2 was lower in HH than NH, which were both lower than in NN. Heart rate was higher in HH than NH, which were both higher than in NN. TFAM was unaltered in normobaric normoxia but increased after HH and NH exposure with no differences between HH and NH. MSTN decreased from pre- to post-exercise in all conditions and was lower in HH compared to NH and NN. Conclusion: Recovery in HH after exercise appears to have a greater effect on muscle oxygen transport than NH. Furthermore, MSTN tends to be further attenuated in HH than NH. Caution should be used when translating data obtained in a NH environment to a HH environment.
Skeletal Muscle mRNA Response to Hypobaric and Normobaric Hypoxia After Exercise
Dr. C.C. and Mabel L. Criss Library
Environmental stimuli such as temperature and hypoxia can influence cellular signaling in the skeletal muscle. Previously we have reported no changes in gene expression related to mitochondrial development with acute exposure to normobaric hypoxia. However, exposure to hypobaric hypoxia may elicit different physiological responses. Purpose: To determine the effects of recovery in hypobaric hypoxia (HH), normobaric hypoxia (NH), and normobaric normoxia (NN) after exercise on gene expression related to mitochondrial biogenesis, myogenesis, and proteolysis. Methods: Recreationally trained participants (8 male, 7 female) each completed three trials of 1-h cycling at 70% of Wmax. Following exercise, participants sat in an environmentally controlled chamber for a 4-h recovery period in NN (975 m), NH (4,420 m), or HH (4,420 m) environmental conditions. Muscle biopsies were taken from the vastus lateralis pre-exercise and after a 4-h environmental exposure period. Samples were analyzed using qRT-PCR. Results: SpO2 was lower in HH than NH, which were both lower than in NN. Heart rate was higher in HH than NH, which were both higher than in NN. TFAM was unaltered in normobaric normoxia but increased after HH and NH exposure with no differences between HH and NH. MSTN decreased from pre- to post-exercise in all conditions and was lower in HH compared to NH and NN. Conclusion: Recovery in HH after exercise appears to have a greater effect on muscle oxygen transport than NH. Furthermore, MSTN tends to be further attenuated in HH than NH. Caution should be used when translating data obtained in a NH environment to a HH environment.