Award Date

May 2018

Degree Type

Thesis

Degree Name

Master of Science (MS)

Department

Kinesiology and Nutrition Sciences

First Committee Member

James Navalta

Second Committee Member

Brian Schilling

Third Committee Member

John Young

Fourth Committee Member

Graham McGinnis

Fifth Committee Member

Jennifer Pharr

Number of Pages

45

Abstract

Introduction: Telomerase reverse transcriptase (TERT) is the enzyme that adds telomeric sequences to the end of linear chromosomes. Exercise has shown to upregulate acutely leukocyte TERT after just 30 minutes of running on a treadmill at 80% of VO2max (Denham et al., 2016). Hypoxia inducible factor 1 (HIF-1) is also a mediator of TERT in in vitro (Nishi et al., 2004). Moderate acute exposure to hypoxia was associated with substantial increases in plasma TERT in a recent study on rats (Wang et al., 2014). The specific aim of the current study was to identify if acute hypoxia upregulates plasma TERT in healthy adult humans. We hypothesized that TERT would be increased after cycling exercise and that exercise in hypoxia would illicit a greater increase than exercise alone.

Methods: Ten healthy adults (5 male, 5 females 23.8 ± 4.5 yrs.) volunteered for the study. Each participant visited the lab on three separate occasions separated by 72 hours but no more than 2 weeks. The conditions were defined as normoxia (FiO2 = 20.5%) and normobaric hypoxia (FiO2 = 14.4%) created by Altitude simulation machine. On the first visit, graded exercise tests (GXT) were performed in each condition to determine the resistance at 75% of age predicted maximum heart rate (HRmax) by cycling on a cycle ergometer at 60 revolutions per minute. Exercise trials took place on subsequent visits, conditions were counterbalanced and randomized. Exercise trials were defined as 30 minutes cycling at 60 RPM at an intensity set to 75% of age predicted HRmax. 600 µL blood samples were taken from finger stick immediately before and 30 minutes after completion of exercise trials. Blood samples were then centrifuged and plasma aliquoted and stored at -80°C until all samples were collected for later analysis. Statistical significance was accepted at p < 0.05.

Results: ELISA analysis did not detect any levels of TERT in the plasma samples for any of the unknowns. Work load was decreased in hypoxia compared to normoxia (110.7 ± 34.5 W, 125.8 ± 49.6 W, p = 0.04) but mean exercise heart rate was not different between conditions (144.4 ± 4.5 BPM, 146.9 ± 5.5 BPM, p = 0.065).

Discussion: Plasma TERT is not detectable by ELISA analysis in healthy adults. Intensity was matched between conditions and confirmed by mean heart rate. Further research is needed to determine if hypoxia has an effect on TERT in human tissue.

Keywords

Hypoxia; Plasma; Telomerase

Disciplines

Medical Physiology | Medicine and Health Sciences | Physiology

Language

English


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