Plasma, tissue and fecal cholesterol of young pigs fed restricted or liberal amounts of beef, soy or conventional diets

Comparison of glycerolipid biosynthesis in homogenates from human, ovine, bovine and rat adipose tissue in vitro

1. Assay conditions were compared for glycerolipid biosynthesis in homogenates prepared from human abdominal, ovine and bovine subcutaneous, and rat epididymal adipose tissues. 2. In contrast to other species, longer incubation time and greater homogenate concentration resulted in decreased glycerolipid biosynthesis with rat adipose tissue homogenates. 3. Species differences were observed in concentration-dependency for ATP and fatty acids (palmitate, oleate and palmitoleate). 4. Results indicated that glycerolipid biosynthesis transpired at different rates in the four species, and that ovine and human adipose tissue homogenates had similar properties.

The domestic goat: a useful model to determine effects of diet and exercise on cholesterol accumulation in the body

1. Young goats were used to study factors contributing to atherosclerosis. 2. Cholesterol in egg yolk affected plasma cholesterol concentration more than did a similar amount of crystalline cholesterol in the diet. 3. Goats fed high fat diets developed fatty lesions in their aortas. 4. Cholesterol concentration in low-density lipoprotein was greatest in goats fed restricted-calorie diets without exercise, but least in goats fed liberally and exercised. 5. Cholesterol concentration in liver and fat deposition in aorta were greatest in the restricted-calorie, no exercise regime.

Effects of dietary beef and soy protein on tissue composition and low density lipoprotein uptake in young pigs

To study effects of dietary protein source on plasma cholesterol homeostasis, six littermate pairs of 8-wk-old, castrated male pigs were assigned randomly to high fat diets containing either lean beef or soy protein isolate, with beef tallow as the major fat source in both diets. Diets were fed for 6 wk, with blood samples taken weekly and analyzed for lipid composition. At 6 wk, each pig was injected with [3H]cholesterol- and [14C]sucrose-labeled low density lipoproteins, and serial blood samples were taken. Pigs were then killed, and several tissues were sampled. Results show that dietary beef or soy protein, when fed with beef tallow as a fat source, has differential effects on rates of uptake of intact LDL by heart, M. sartorius muscle and subcutaneous adipose tissue, and on rates of uptake of LDL cholesterol by net free cholesterol exchange in subcutaneous and perirenal adipose tissues. Dietary protein source affected the composition of only two tissues analyzed. Pigs fed the beef-based diet had greater lipid concentrations in M. sartorius muscle, whereas pigs fed the soy protein-based diet had greater lipid concentrations in heart. Source of dietary protein did not influence in vivo kinetics of LDL cholesterol removal from blood plasma.