Abstract
The modulation of lipoprotein lipase (LPL) activity and mass was examined in rats with insulin resistance induced by a beef tallow diet. Male sprague-Dawley rats were meal-fed an isoenergetic diet based on either beef tallow or safflower oil for an 8-week period. Insulin resistance brought about by long-term feeding of a beef tallow diet was confirmed by an oral glucose tolerance test. Plasma glucose and insulin levels were higher at almost all times of day in the rats fed the beef tallow diet than in those fed the safflower oil one. LPL activities of the skeletal and cardiac muscles and brown adipose tissue before and after a meal were lower in the beef tallow diet group than in the safflower oil diet group, however those of the perirenal and subcutaneous adipose tissues were not different between the two dietary groups. The amounts of LPL proteins in the soleus muscle and perirenal adipose tissue corresponded to the enzyme activities in these tissues. These results suggest that the effect of dietary saturated fat on LPL activity and mass are different in muscles and adipose tissues and that generalized peripheral insulin resistance, induced by feeding rats a beef tallow diet for a sufficient duration, is not followed by an impairment of the modulation of LPL activities and protein amount.
