Zusammenfassung

Skeletal muscle is the tissue most responsible for basal and exercise induced energy expenditure and is commonly investigated to provide insights into human physical performance and diseases such as obesity and diabetes. The newly discovered uncoupling protein-3 (UCP3) is believed to play a role in energy dissipation in skeletal muscle. However, degree of expression, regulation and function in the individual muscle fiber types is unknown. We will develop an in situ hybridization technique that will be used to semi-quantify the mRNA and protein expression of UCP3 in fast and slow twitch muscle fibers. This technique will allow, first, to study the possible effects of endurance training on UCP3 expression in human vastus lateralis fast and slow twitch muscle fibers, and second, to test the hypothesis that a correlation exists between the decrease in muscle metabolic efficiency observed during high intensity submaximal exercise, called the slow component of VO2 kinetics, and UCP3 expression in vastus lateralis fast and slow twitch muscle fibers.