The Acute Effects of Exercise and Temperature on Regional mtDNA
Mark L McGlynn1, Halee Schnitzler1, Robert Shute1
1School of Health and Kinesiology, University of Nebraska at Omaha, Omaha, NE 68182, USA.
Abstract:
A reduced mitochondrial DNA (mtDNA) copy number, the ratio of mitochondrial DNA to genomic DNA (mtDNA:gDNA), has been linked with dysfunctional mitochondria. Exercise can acutely induce mtDNA damage manifested as a reduced copy number. However, the influence of a paired (exercise and temperature) intervention on regional mtDNA (MINor Arc and MAJor Arc) are unknown. Thus, the purpose of this study was to determine the acute effects of exercise in cold (7 °C), room temperature (20 °C), and hot (33 °C) ambient temperatures, on regional mitochondrial copy number (MINcn and MAJcn). Thirty-four participants (24.4 ± 5.1 yrs, 87.1 ± 22.1 kg, 22.3 ± 8.5 %BF, and 3.20 ± 0.59 L·min-1 VO2peak) cycled for 1 h (261.1 ± 22.1 W) in either 7 °C, 20 °C, or 33 °C ambient conditions. Muscle biopsy samples were collected from the vastus lateralis to determine mtDNA regional copy numbers via RT-qPCR. mtDNA is sensitive to the stressors of exercise post-exercise (MIN fold change, -1.50 ± 0.11; MAJ fold change, -1.70 ± 0.12) and 4-h post-exercise (MIN fold change, -0.82 ± 0.13; MAJ fold change, -1.54 ± 0.11). The MAJ Arc seems to be more sensitive to heat, showing a temperature-trend (p = 0.056) for a reduced regional copy number ratio after exercise in the heat (fold change -2.81 ± 0.11; p = 0.019). These results expand upon our current knowledge of the influence of temperature and exercise on the acute remodeling of regional mtDNA.
Related Concept Videos
Factors Affecting Body Temperature
Factors may include:
Requirements for Human Life
Oxygen
Atmospheric air is only about 20 percent oxygen, but that oxygen is a key component of the chemical reactions that keep the body alive, including the reactions that produce ATP. Brain cells are susceptible to a lack of oxygen because they require a...
Exercise and Cardiovascular Response
Light to moderate physical activity initiates a series of interconnected responses in the body. The heart rate modestly increases in anticipation of the workout, followed by widespread vasodilation as oxygen consumption by skeletal muscles increases. This results in decreased peripheral resistance, increased capillary blood flow, and accelerated...
Body Temperature
The average body temperature is approximately 37°C (98.6°F) and typically ranges from 36.1–37.2°C...
Body Temperature
Background and Environment Affect Phenotype
An example of how genetic background affects phenotype can be seen in horses. The Extension gene in horses is responsible for their coat color. A wild-type gene (EE) produces black pigment in the coat, while a mutant gene (ee) produces red pigment. A...


