Document Type
Dissertation
Degree Name
Doctor of Philosophy (PhD)
Department
Kinesiology and Physical Education
Faculty/School
Faculty of Science
First Advisor
Tom Hazell
Advisor Role
Primary Supervisor
Abstract
Once considered metabolic waste produced during exercise, lactate is now known to have diverse roles in biology. Muscle-derived lactate can travel through the bloodstream and be taken up by other tissues and i) oxidized, ii) converted to glucose via gluconeogenesis, or iii) bind to its receptor to trigger molecular signaling cascades. Lactate has been described as a “myokine” capable of inter-organ crosstalk and compelling evidence demonstrates lactate’s role as a signalling molecule in pathways related to the regulation of appetite. The purpose of this dissertation was to further elucidate lactate’s role in appetite regulation using series of studies aimed at manipulating lactate concentrations while attempting to minimize other extraneous factors that could influence appetite regulation. The main findings of this dissertation include: 1) oral sodium lactate ingestion does not increase blood lactate concentrations and is not an effective way to assess lactate’s effects on metabolism (Study #1); 2) using human studies with exercise intensity or a different exercise modality (resistance training) demonstrated exercise-induced lactate accumulation coincides with reductions in acylated ghrelin (Studies #2 & #3); 3) using a systematic review of all available work on exercise-induced lactate accumulation and post-exercise acylated ghrelin concentrations, statistical synthesis demonstrates an association between lactate and the acylated ghrelin (Study #4); 4) blood lactate accumulation following exercise does not alter the appetite regulating neuropeptides (or that peripheral blood samples do not reflect the central concentrations) (study #5); and finally 5) lactate accumulation due to exercise, injection, or oxamate administration (lactate dehydrogenase inhibitor) in a mouse-model does not alter the signaling cascades involved in appetite regulation. Overall, the results of this dissertation have improved our understanding of lactate’s role in appetite regulation and will guide future research necessary to fully elucidate the involvement of lactate in appetite-regulation.
Recommended Citation
McCarthy, Seth, "Lactate's Role in Appetite Suppression" (2025). Theses and Dissertations (Comprehensive). 2726.
https://scholars.wlu.ca/etd/2726
Convocation Year
2025
Convocation Season
Spring