Non-Invasive Detection of Anaerobic Metabolism in Exercising Muscle Using Proton MRI

The second, and major, component of this thesis concerned the exercise-induced increases the 1H T2 of muscle water. The hypotheses were tested that the T2 increase results from increased intracellular volume (VI), decreased intracellular pH (pHI), and/or changes in magnetization transfer (MT) or other longitudinal relaxation mechanisms. Isolated frog gastrocnemii were treated with iodoacetate (IAA; to inhibit lactate production), NaCN (to maximize lactate production), or left untreated and then performed 60 1s/min maximal isometric contractions. The intracellular transverse relaxation time (T2,I increased more in NaCN-treated and untreated muscles than in IAA-treated muscles. The VI increase and pHI decrease were greater in NaCN-treated and untreated muscles than in IAA-treated muscles. There was no change in the MT ratio and a slight decrease in T1 following exercise. In separate experiments, V I and pHI were manipulated in non-exercising sartorii and quantitative relationships were developed between these variables and T 2,I. A multiple regression model shows that 62% of the variance in the T2,I change of exercise is accounted for by these two variables.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Molecular and Integrative Physiology

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2015

Author dc:creator

• Damon, Bruce Murray

Contributors dc:contributor

• Dawson, M. Joan

• Health Sciences, Radiology

Language dc:language

eng

Identifier

(MiAaPQ)AAI9971061

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/87273