Serum lipoproteins of the Zucker rat in response to an endurance running program.

Previous studies have concluded that exercise training has resulted in increases in cholesterol associated with high-density lipoprotein (HDL). However, data regarding alterations in triglyceride, cholesterol, and the protein associated with the three major lipoproteins in a hyperlipoproteinemic state in response to exercise training are not available. Serum lipoprotein levels from normal and hyperlipoproteinemic Zucker rats were studied following 9 and 18 wk of treadmill running to determine the extent that the three major serum lipoprotein classes were affected. Nine weeks of treadmill running reduced serum triglyceride content in obese rats (sedentary, 294 +/- 19 [SE]; trained, 128 +/- 40 mg X dl-1) but did not affect total serum cholesterol (sedentary, 85 +/- 6; trained, 90 +/- 6 mg X dl-1). Serum very low-density lipoprotein from the trained obese rats contained lower levels of triglyceride (57%), cholesterol (46%), and protein (61%). HDL cholesterol (sedentary, 61 +/- 4; trained, 73 +/- 4 mg X dl-1) was increased by 14% in the obese rat. In the lean rat, HDL cholesterol was the only lipoprotein fraction altered following 9 wk of treadmill running. The data from this study indicate that hypertriglyceridemia can be reduced in the obese rat and that HDL cholesterol can be increased by physical activity requiring about 70% maximal aerobic capacity.