Beef tallow diet decreases lipoprotein lipase activities in brown adipose tissue, heart, and soleus muscle by reducing sympathetic activities in rats

Abstract

Effects of dietary fats consisting of different fatty acids on lipoprotein lipase activities in the interscapular brown adipose tissue, heart, and soleus muscle, and on body fat accumulation were studied in rats. Sprague-Dawley male rats were meal-fed an isoenergetic diet based on either beef tallow or safflower oil for 8 weeks. Lipoprotein lipase activities in the interscapular brown adipose tissue, heart, and soleus muscle before and after a meal were lower in the beef tallow diet group than in the safflower oil diet group. Body fat accumulation was greater in the beef tallow diet group than in the safflower oil diet group. The norepinephrine turnover rats in the interscapular brown adipose tissue, heart, and soleus muscle were lower in the beef tallow diet group. beta-Adrenergic receptor bindings were determined with [125I]iodocyanopindolol. Binding affinities of beta-adrenergic receptor in the interscapular brown adipose tissue, heart, and soleus muscle were lower in the beef tallow diet group probably resulted from lower membrane fluidities. These results suggest that intake of the beef tallow diet promotes body fat accumulation by reducing the lipoprotein lipase activities resulting from lower sympathetic activities in the brown adipose tissue, heart, and skeletal muscle.