The effect of plasma low density lipoprotein apheresis on the hepatic secretion of biliary lipids in humans.

Background: The liver is a key organ in the metabolism of cholesterol in humans. It is the only organ by which substantial amounts of cholesterol are excreted from the body, either directly as free cholesterol into the bile or after conversion to bile acids. The major part of cholesterol synthesis in the body occurs in the liver.

The influence of age on low density lipoprotein metabolism: effects of cholestyramine treatment in young and old healthy male subjects.

Objective: The plasma concentration of low density lipoproteins (LDL) increases with age, mainly as the result of a reduced clearance of LDL. Because the conversion of cholesterol to bile acids is reduced with age, we hypothesized that the response of plasma LDL to stimulation of bile acid production would be different in young and old subjects.

Design, Subjects And Setting: Comparison of the response to cholestyramine treatment in two groups of normolipidaemic, normal weight males: seven young (23-34 years) and eight old (64-73 years).

Circulating markers for biosynthesis of cholesterol and bile acids are not depressed in asymptomatic gallstone subjects.

Background/aims: Cholesterol gallstone disease is often associated with an increased biliary secretion rate of cholesterol, which may be due to abnormalities in hepatic cholesterol metabolism. The aim of the present study was to investigate whether gallstone subjects may have an underlying defect in hepatic cholesterol and bile acid formation.

Methods: In 41 asymptomatic gallstone subjects, randomly selected from a population of both sexes 40 and 60 years of age, and in 72 age- and sex-matched controls, plasma levels of lathosterol (reflecting hepatic HMG CoA reductase activity) and 7alpha-hydroxy-4-cholesten-3-one (reflecting cholesterol 7alpha-hydroxylase activity) were analysed.

Hepatic cholesterol metabolism in human obesity.

Hepatic cholesterol metabolism was studied in operative liver biopsies from 17 morbidly obese subjects and compared with that in samples from 15 nonobese controls. The aim was to understand the mechanisms causing the hypersecretion of cholesterol into bile. The content of cholesteryl esters was increased threefold in the liver of obese subjects compared with that of the controls (P < .

The effect of vitamin C in high doses on plasma and biliary lipid composition in patients with cholesterol gallstones: prolongation of the nucleation time.

Vitamin C deficiency in guinea pigs leads to cholesterol supersaturation of bile and formation of cholesterol gallstones. It has been suggested that there may also exist an association between vitamin C and cholesterol gallstones in man, but such a relationship has not been studied in gallstone patients. In order to study the possible effects of vitamin C on gallstone disease in humans, plasma lipid levels, hepatic cholesterol metabolism, biliary lipid composition, cholesterol saturation and nucleation time of gallbladder bile were analysed in 16 consecutive gallstone patients, who were planned for laparoscopic cholecystectomy and were treated with vitamin C (500 mg, four times a day) for 2 weeks before surgery.