Cholesterol Metabolism in Mature and Immature Rats Fed Animal and Plant Protein

Abstract

In two feeding experiments immature (180 g) and mature rats (370 g) were fed a semi-purified diet containing 20% of a protein source (casein, wheat gluten, soybean or potato protein) for 4 wk. Food supply was restricted to 15 g daily. As compared to casein, plant proteins induced significantly lower concentrations of plasma total cholesterol and high density lipoprotein (HDL) cholesterol. The plasma cholesterol increase associated with aging was not prevented by consumption of casein, soybean or potato protein, but wheat gluten seemed to be effective. Lecithin-cholesterol acyltransferase (LCAT) activity was not significantly different in rats of the same age fed different plant proteins, whereas the esterification rate was lower in rats fed casein. With aging the LCAT activity generally decreased. As compared to the casein groups, the rats fed plant proteins showed higher excretion of fecal neutral and acidic steroids. Among the groups fed plant proteins, the fecal output of steroids was variable. Significantly negative correlations were found between fecal total sterol excretion and plasma total cholesterol or HDL cholesterol, respectively. Plant proteins showed a faster migration rate in the stomach, whereas their migration and absorption were slower in the first half of the small intestine. A relation between nonabsorbed nitrogen-containing substances and sterol excretion was hypothesized.

Nutritional evaluation of protein isolate from rubber seed in the diet of Labeo rohita : Effects on growth performance, nutrient utilization, whole body composition and metabolic enzymes activity

“…Plant products have been reported to have a hypocholesteromic effect in human, terrestrial animal, and fish (Lees et al, 1977;De Schrijver, 1990;Kaushik et al, 1995). The present study clearly showed that dietary RPI inclusion gradually reduce serum cholesterol levels in L. rohita fingerlings.…”

Response of young pigs to feeding potato protein and potato fibre - nutritional, physiological and biochemical parameters

“…The greater absorption was accompanied by higher blood levels of triglycerides in pigs fed on PPC than on CAS while the total cholesterol concentration did not differ. These findings are contradictory to the hypolipidaemic effect of potato protein observed in rats (De Schrijver, 1990) and its hypocholesterolaemic but not hypolipidaemic, effect found in pigs (Spielmann et al, 2009). Pigs and not rats, are considered as a better model of lipid metabolism when related to humans.…”

Effect of White Wheat Bread Containing Sugar Beet Fiber on Serum Lipids and Hepatic mRNA in Rats Fed on a Cholesterol-Free Diet

“…De Schrijver has reported that the plasma cholesterol concentration in rats fed with plant protein such as wheat gluten was significantly lower than that in those fed casein, and that this result was caused by the excretion of fecal neutral steroids and bile acid. 26) In this study, wheat gluten and dietary fiber in the bread might have been related to the lipid metabolism. 23,26) The liver cholesterol concentration in the BP group was significantly (P < 0:05) higher than that in the CN group; although the reason for this remains unclear, it may be speculated that the increase in liver cholesterol concentration was due to the lower acidic sterol excretion by the BP group than by the BBP group.…”