To determine whether the mechanisms of plasma LDL lowering by dietary fiber are related to effects on apo B secretion rates or intravascular processing of lipoproteins (LP), guinea pigs were fed semipurified diets containing cellulose (12 5%), PE (12.5%), guar gum (12.5%) or PSY (7.5%) (w/w). Dietary fiber lowered plasma cholesterol (P < 0.01) from 32 to 57%. Triacylglycerol (TAG) secretion rates measured after intravenous injection of triton 1339 were not different among groups. However, apo B secretion rates were lowered 27 to 42% by dietary fiber with GG having the most pronounced effect (P < 0.01). Nascent VLDL from animals fed PE, GG or PSY contained more TAG/ particle and mature VLDL was characterized by lower concentrations of free and esterified cholesterol compared to VLDL isolated from control animals. In addition, plasma lecithin cholesteryl acyl transferase and choîesteryl ester transfer protein activities were reduced by dietary fiber (P < 0.01) suggesting that modifications in LP composition induced by dietary fiber result not only from differences m secreted particles but also from LP intravascular processing . [Supported by The Arizona Disease Control Research Commission].
|Original language||English (US)|
|State||Published - 1996|
ASJC Scopus subject areas
- Molecular Biology