Date Thesis Awarded

4-2014

Document Type

Honors Thesis

Degree Name

Bachelors of Science (BS)

Department

Kinesiology & Health Sciences

Advisor

Brennan Harris

Committee Members

Randolph Coleman

Scott Ickes

Abstract

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.

Creative Commons License

Creative Commons Attribution-Noncommercial-No Derivative Works 4.0 License
This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 4.0 License.

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