Date Thesis Awarded
Bachelors of Science (BS)
Kinesiology & Health Sciences
Previously, we have demonstrated a dramatic increase in mitochondrial biogenesis in skeletal muscle of rats exercise trained while maintaining a constant core temperature. In this study, we explored the potential mechanisms of increased mitochondrial biogenesis in this model by examining the expression of PGC-1α, AMPK, eNOS, SIRT1 and SIRT3. Female, Sprague-Dawley rats (5 mos of age) were divided into three groups sedentary (S), exercise in 22°C room (ET), and exercise while maintaining core temperature (E). Exercised animals trained for 5 weeks on a motor-driven treadmill at 30 m/min, 60 min/day, and 5 days/wk during the final 2 weeks. Core temperature was held constant in E by reducing room temperature to 6-8°C. Mitochondrial biogenesis was increased in cold-trained animals versus room temperature-trained animals as indicated by a significant (P<0.05) increase in cytochrome oxidase activity in the cold training group. Hsp70 expression was significantly (P< 0.05) increased in both ET and E rats versus SED, but ET was also significantly (P< 0.05) higher than the E group. Cold training was also less stressful than regular exercise; serum LDH was significantly (P< 0.05) elevated among ET tissues versus E tissues. There was no difference in PGC-1α, AMPK, or eNOS expression between any of the groups. SIRT1 was significantly (P< 0.05) decreased in rats trained at room temperature (ET), but unchanged in cold-trained rats (E). SIRT3 expression was significantly (P< 0.05) increased in rats trained at both room temperature and between 6-8°C, but no difference was observed between the two. The results of this study indicate that the effect of core temperature alters the pathway by which mitochondrial biogenesis occurs.
Hodge, Taylor M., "Effects of core temperature on exercise-induced mitochondrial biogenesis: Potential role of PGC-1α, AMPK eNOS, SIRT1, and SIRT3" (2014). Undergraduate Honors Theses. Paper 39.