Plasma Cholesterol Esterification in Vivo in Man

Abstract

The turnover of plasma-esterified cholesterol can be measured in vivo after injection of radiomevalonate. Values obtained in vivo are similar to measurements made in vitro. Esterification of cholesterol occurs mainly in plasma: when cholesterol synthesis is stimulated, newly formed cholesterol enters plasma predominantly unesterified. When cholesterol turnover is increased, plasma cholesterol-esterifying activity rises proportionately. The turnover of esterified cholesterol is increased in obesity, in Type 4 hyperlipoproteinaemia, and during carbohydrate-rich diets; since the turnover of lipoproteins, especially VLDL, is probably also increased under these conditions, esterified cholesterol appears to have an important role in plasma lipid transport.

Key Words:

• Carbohydrate diets
• esterified cholesterol turnover
• hyperlipoproteinaemia
• obesity