Ratio of lathosterol to campesterol in serum predicts the cholesterol-lowering effect of sitostanol-supplemented margarine.

Objective: Plant sterol/stanol margarines are recommended as a lipid-lowering dietary supplement in the treatment of hypercholesterolemia. Parameters predicting the individual cholesterol-lowering effect have not been elucidated so far. Therefore, we investigated the responsiveness to sitostanol-supplemented margarine in a specially selected population.

Comparison of the intestinal uptake of cholesterol, plant sterols, and stanols in mice.

The recent identification of the aberrant transport proteins ABCG5 and ABCG8 resulting in sitosterolemia suggests that intestinal uptake of cholesterol is an unselective process, and that discrimination between cholesterol and plant sterols takes place at the level of sterol efflux from the enterocyte. Although plant sterols are structurally very similar to cholesterol, differing only in their side chain length, they are absorbed from the intestine to a markedly lower extent. In order to further evaluate the process of discrimination, three different sterols (cholesterol, campesterol, sitosterol) and their corresponding 5 alpha-stanols (cholestanol, campestanol, sitostanol) were compared concerning their concentration in the proximal small intestine, in serum, and in bile after a single oral dose of deuterated compounds.

Evidence that leptin contributes to intestinal cholesterol absorption in obese (ob/ob) mice and wild-type mice.

In the present study, the effect of leptin on intestinal cholesterol absorption was investigated in C57 BL/6 OlaHsd Lep(ob)/Lep(ob) obese (ob/ob) mice and lean C57 BL/6 (wild-type) mice. Animals were treated either with or without recombinant leptin for 2 wk. Cholesterol absorption was measured by the constant isotope feeding method and indirectly by the ratio of campesterol to cholesterol in serum.

ATP-binding cassette transporter A1 (ABCA1) affects total body sterol metabolism.

Background And Aims: Members of the family of ABC transporters are involved in different processes of sterol metabolism, and ABCA1 was recently identified as a key regulator of high-density lipoprotein (HDL) metabolism. Our aim was to further analyze the role of ABCA1 in cholesterol metabolism.

Methods: ABCA1-deficient mice (ABCA1-/-) and wild-type mice were compared for different aspects of sterol metabolism.

Intestinal absorption of cholesterol, transport in the haemolymph, and incorporation into the fat body and Malpighian tubules of the larval dragonfly Aeshna cyanea.

Doses of 1.5 mumol cholesteryl oleate ingested by Aeshna cyanea larvae were partially hydrolysed in the intestinal lumen and the liberated oleic acid absorbed, while free cholesterol and unhydrolysed cholesteryl oleate were eliminated in the faeces. Ingestion of [4-14C]cholesterol dissolved in olive oil revealed that the larvae also absorbed free cholesterol, the minor part of which (up to 12%) was esterified in the midgut epithelium.