Skeletal Muscle and Post-Heparin Plasma Lipoprotein Lipase Activities (Exercise, Triglyceride)

Lipoprotein lipase (LPL) is the extrahepatic enzyme responsible for the clearance of plasma triglycerides (TG). The LPL activity of adipose tissue, but not skeletal muscle, has been studied extensively. Although a quantitative relationship between LPL activity, plasma TG levels and the rate of plasma TG removal has not been substantiated, subtle changes in the LPL activities of specific tissues are often reported as being indicative of changes in the efficiency of plasma TG removal and/or changes in TG-derived fatty acid uptake by tissues. This thesis examined the physiological significance of changes in the LPL capacities of skeletal muscles and adipose tissue, and post-heparin plasma (PHP) in rats using experimental conditions of diet and exercise. Starvation decreased adipose tissue LPL activity, but had little effect on muscles. Refeeding stimulated activity in adipose tissue by +300%. High-carbohydrate feeding stimulated adipose LPL, but did not alter body fat deposition. Exercise training (at approximately 80% VO(,2) max) stimulated LPL activities of red skeletal muscles, but did not alter the total lipid content of muscle and did not affect the rate of clearance of plasma TG, as determined using intravenous lipid infusion. Lipid and extensive heparin infusions did not deplete PHP LPL activity or in vitro tissue LPL activity. Thus, under physiological diet and exercise conditions, the rat appears to be capable of maintaining plasma and tissue LPL levels and in vitro measures of LPL capacity do not appear to directly reflect changes in the rate of plasma TG clearance or TG-derived fatty acid uptake by peripheral tissues.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Food Science

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2015

Author dc:creator

• Quig, David William

• Health Sciences, Nutrition

Language dc:language

eng

Identifier

(UMI)AAI8521864

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/77452