Changes in muscle lipoprotein lipase activity during exercise in dogs fed on a mixed fat-rich meal.

Skeletal muscle lipoprotein lipase activity LPLA was compared in dogs performing prolonged treadmill exercise after 20-22 h fasting or 4 h following mixed fat-rich meal ingestion. In the fasting state muscle LPLA increased progressively during 2 h exercise. In fed dogs the resting value of the muscle LPLA was considerably lower than that in the fasting state, and no increase in the enzyme activity occurred during physical effort. The inhibition of the muscle LPLA by the meal ingestion can be attributed to the persisting effects of increased plasma insulin and/or FFA concentrations, found at the beginning of exercise.