Vitamin D is an important physiologic regulator of bone and mineral metabolism. In chronic kidney disease, reduced renal production of calcitriol contributes to secondary hyperparathyroidism (SHPT). Consequently, supplementation with vitamin D sterols is an important treatment for SHPT and its associated mineral and bone disorders. However, doses of vitamin D sterols required to suppress parath...

Several studies have shown that increased levels of low-density lipoprotein (LDL) cholesterol predict cardiovascular events. The Adult Treatment Panel II (ATP II) introduced the principle of therapeutic lifestyle changes, including plant sterols/stanols for the management of LDL cholesterol. Plant sterols and stanols in fat matrices effectively lower LDL cholesterol levels in hypercholesterolem...

Sterols are important components of many biological membranes, and changes in sterol levels can have dramatic effects on membrane properties. Sterols are transported rapidly between cellular organelles by vesicular and nonvesicular processes. Recent studies have identified transmembrane proteins that facilitate the removal of sterols from membranes as well as soluble cytoplasmic proteins that p...

Sterols are moved between cellular membranes by nonvesicular pathways whose functions are poorly understood. In yeast, one such pathway transfers sterols from the plasma membrane (PM) to the endoplasmic reticulum (ER). We show that this transport requires oxysterol-binding protein (OSBP)-related proteins (ORPs), which are a large family of conserved lipid-binding proteins. We demonstrate that a...

A number of studies have raised the possibility of circulating plant sterols being a risk factor in the pathogenesis of atherosclerosis. Evidence in support of this hypothesis comes mainly from observations in sitosterolemic patients, who hyperabsorb plant sterols and suffer premature atherosclerosis. Accordingly, the atherogenicity of plant sterols of dietary origin is currently under debate, ...

We read with interest the paper by Miettinen et al. (1) demonstrating that the higher the absorption of cholesterol, the higher the plant sterol contents are in serum resulting in their higher contents in atherosclerotic plaque. The prospective Cardiovascular Munster (PROCAM) study found that people in the upper quartile of sitosterol levels had a 1.8-fold increased risk of major coronary event...

ion from the –CH2– groups in a-position to a C@C double bond (C7–H in D-sterols, C23–H in the two avenasterols and D-fucosterol, C6–H in D-sterols, or C23–H in D-gramisterol, D-episterol and D-citrostadienol). In the case of 2-propene, the experimentally determined BDE for CH2@CH–CH2–H bond (370 ± 2) kJ mol 1 was practically identical with the C6H5CH2–H BDE for toluene due to the conjugation in...

Recent studies demonstrate that the actual interactions of polyenes with membrane sterols are the basis for their antimycotic toxicity and not, as previously assumed, their potential to form pores. Therefore, sterols must play a vital role in membranes and this function is seriously disturbed once polyenes bind to and/or sequester them. Essential membrane proteins obviously require sterols for ...

Accumulation of 14alpha-methylated sterols or delta8-sterols in Ustilago maydis affected three aspects of the plasma membrane H+-ATPase. Proton transport was reduced in delta8-sterol-accumulating samples, due to an altered H+/ATP stoichiometry. ATP hydrolytic activity was increased, but no direct correlation with the extent or type of abnormal sterol accumulated could be drawn. Finally, Western...

The Federal Institute for Risk Assessment (BfR) below assesses a study from the Netherlands which provides valuable information on the unwanted effects of plant sterols on human retinal microvessels. Retinal vessels analysis is increasingly used for early diagnosis of cardiovascular risks. The findings of the study indicate that intake of plant sterols may entail cardiovascular risks for health...