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The acute effects of differential dietary fatty acids on PDHa activity in human skeletal muscle at the onset of exercise

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dc.contributor.author Bradley, Nicolette Shannon. en_US
dc.date.accessioned 2009-06-29T14:36:58Z
dc.date.available 2009-06-29T14:36:58Z
dc.date.issued 2006-06-29T14:36:58Z
dc.identifier.uri http://hdl.handle.net/10464/1659
dc.description.abstract Pyruvate dehydrogenase (PDH) is an important regulator of carbohydrate oxidation during exercise and its activity can be down-regulated by an increase in dietary fat. The purpose of this study was to determine the acute metabolic effects of differential dietary fatty acids on the activation of PDH in its active form (PDHa) at rest and at the onset of moderate-intensity exercise. University-aged male subjects (n=7) underwent 2 fat loading trials spaced at least 2 weeks apart. Subjects consumed saturated (SFA) or polyunsaturated (PUFA) fat over the course of 5 hours. Following this, participants cycled at 65% VO2 max for 15 min. Muscle biopsies were taken prior to and following fat loading and at 1 min exercise. Plasma free fatty acids increased from 0.15 ± 0.07 to 0.54 ± 0.19 mM over 5 hours with SFA and from 0.1 1 ± 0.04 to 0.35 ±0.13 mM with PUFA. PDHa activity was unchanged following fat loading, but increased at the onset of exercise in the SFA trial, from 1 .4 ± 0.4 to 2.2 ± 0.4 /xmol/min/kg wet wt. This effect was negated in the PUFA trial (1 .2 ± 0.3 to 1 .3 ± 0.3 pimol/min/kg wet wt.). PDH kinase (PDK) was unchanged in both trials, suggesting that the attenuation of PDHa activity with PUFA was a result of changes in the concentrations of intramitochondrial effectors, more specifically intramitochondrial NADH or Ca^*. Our findings suggest that attenuated PDHa activity participates in the preferential oxidation of PUFA during moderateintensity exercise. en_US
dc.language.iso eng en_US
dc.publisher Brock University en_US
dc.subject Pyruvate kinase. en_US
dc.subject Fatty acids. en_US
dc.subject Fatty acids in human nutrition. en_US
dc.subject Muscle proteins. en_US
dc.subject Muscles en_US
dc.subject Exercise en_US
dc.title The acute effects of differential dietary fatty acids on PDHa activity in human skeletal muscle at the onset of exercise en_US
dc.type Electronic Thesis or Dissertation en_US
dc.degree.name M.Sc. Applied Health Sciences en_US
dc.degree.level Masters en_US
dc.contributor.department Applied Health Sciences Program en_US


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