Effect of dietary composition on lipids in serum and in liver of rats fed a cystine-excess diet.

Abstract

The effects of dietary composition on lipids in serum and in liver of rats fed with a cystine-excess diet were investigated. When starch was used as the carbohydrate source, the addition of excess-cystine caused an increase in serum cholesterol and phospholipids, and hepatomegaly. Phospholipids in serum of rats fed with a cystine-excess diet containing 5% corn oil were higher than those with a cystine-excess diet that was low in corn oil (0.1%). The addition of konjac mannan and pectin prevented hypercholesterolemia, and the rise in phospholipids in serum was prevented by the addition of konjac mannan. Liver cholesterol (mg/liver/100g of body wt.) increased in rats fed with a cystine-excess diet. The addition of excess cystine to a diet containing sucrose as the carbohydrate source resulted in a marked increase of cholesterol in serum and liver, and a decrease of serum triglycerides. The replacement of starch by sucrose in the cystine-excess diet increased liver cholesterol. Lipids, cholesterol, phospholipids and triglycerides in the liver, but not phospholipids, when expressed as mg per g of liver for rats fed with the diets containing sucrose, increased when compared to those for rats fed with the diets containing starch. In contrast, serum triglycerides increased.