Individual and combined effects of exercise training and dietary fat on myocardial triglycerides in obese mice

Visceral adipose tissue has been suggested to have a stronger association with disease than subcutaneous adipose tissue. This is primarily due to its inflammatory nature. Epicardial adipose tissue is a type of visceral fat located on the exterior of the heart. Recent evidence suggests an association between atherosclerosis, epicardial fat, and hepatic triglyceride deposition. PURPOSE -The purpose of this study was to determine the individual and combined effects of endurance exercise training and changes in dietary fat intake on myocardial triglyceride, a marker of epicardial fat, as well as hepatic triglycerides, another visceral fat depot implicated in CVD and diabetes risk, in a mouse model of dietary induced obesity. METHODS – Male c57BL/6 mice (n=73) fed a 45% high-fat diet for 6-weeks to induce obesity were randomly assigned into four groups: exercise high-fat, exercise low-fat, sedentary high-fat, sedentary low-fat. Exercise intervention consisted of treadmill running for 5 days/week, 40 min/day, at an intensity of 65-70% VO2 max for 12 weeks. After the 12 weeks, animals were sacrificed and both hearts and liver were removed. Using a triglyceride assay, myocardial and liver triglycerides levels were determined. RESULTS – Exercise training significantly lowered liver triglycerides in both high fat and low fat fed mice (p < 0.001 for both groups). However, dietary fat intake did not have a significant effect on liver triglycerides within activity groups. Exercise training also lowered myocardial triglycerides in mice fed a high fat diet (p = 0.005), but had no effect on myocardial triglycerides in mice fed a low fat diet. By contrast, mice fed a low fat diet had significantly lower myocardial triglycerides than high fat fed mice, regardless of activity group (p < 0.01 for both groups). CONCLUSION – Exercise training can attenuate epicardial/myocardial and hepatic fat accumulation in obese mice. Low fat diets can decrease myocardial fat accumulation in obese mice.

Name thesis:degree_name

M.S.

Level thesis:degree_level

Thesis

Discipline thesis:degree_discipline

Kinesiology

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2012

Author dc:creator

• Cortez, Filand

Contributors dc:contributor

• Wilund, Kenneth R.

• Epicardial Fat
• Myocardial Triglycerides
• Exercise

Statement dc:rights

• Copyright 2012 Filand Cortez

Language dc:language

en

Handle dc:identifier

http://hdl.handle.net/2142/30944

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/30944