Requirement of cholesterol for secretion of the very low density lipoprotein (VLDL) by the rat liver

Conference · Fri May 01 04:00:00 EDT 1987 · Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States)

OSTI ID:6326544

Khan, B; Wilcox, H G; Elam, M B; Heimberg, M

Fatty acids stimulate hepatic secretion of VLDL triglyceride (TG) and cholesterol (C), increase C synthesis, and enhance activity of HMG-CoA reductase. Livers from normal fed male rats were perfused for 4 hr in a medium containing 20..mu..Ci (2-/sup 14/C) acetate, 6g/dl serum albumin, 300 mg/dl glucose in Krebs-Henseleit HCO/sub 3/ buffer (pH 7.4), 0-100 ..mu..g/ml mevinolin, and oleate. TG secretion was decreased 0%, 23%, and 32% from control with 1, 10, and 100 ..mu..g/ml mevinolin, respectively; there was no significant effect on C or C ester (CE) secretion. Specific activity (dpm/..mu..mol) of C synthesized from acetate in the liver decreased 67%, 98%, and 99% from control; incorporation into CE decreased 64%, 81%, and 84%, respectively. TG and phospholipid (PL) activities did not change. Synthesis of TG and PL from (1-/sup 14/C) oleate by isolated hepatocytes from normal fed rats was not affected by addition of 0-100 ..mu..g/ml mevinolin. The mass of C and TG in the liver did not change. Preliminary experiments with perfused liver suggest that output of VLDL TG, C, CE, and PL was diminished; the ratio of C/TG and PL/TG in the VLDL was constant, suggesting secretion of fewer VLDL particles with the same composition. These data suggest that mevinolin acutely reduces biosynthesis of C and secretion of the VLDL, presumably because of a requirement of C for synthesis and secretion of the VLDL.

• Research Organization: Univ. of Tennessee, Memphis
• OSTI ID: 6326544
• Report Number(s): CONF-870644-
• Conference Information: Journal Name: Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States) Journal Volume: 46:6
• Country of Publication: United States
• Language: English

Related Subjects

550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ACETATES
ALBUMINS
ALDEHYDES
ANIMALS
BIOLOGICAL FUNCTIONS
BIOSYNTHESIS
BODY
CARBOHYDRATES
CARBON 14 COMPOUNDS
CARBOXYLIC ACID SALTS
CARBOXYLIC ACIDS
CHOLESTEROL
DIGESTIVE SYSTEM
ESTERS
FUNCTIONS
GLANDS
GLUCOSE
HEXOSES
HYDROXY COMPOUNDS
LABELLED COMPOUNDS
LIPIDS
LIPOPROTEINS
LIVER
MAMMALS
MONOCARBOXYLIC ACIDS
MONOSACCHARIDES
OLEIC ACID
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC PHOSPHORUS COMPOUNDS
ORGANS
PERFUSED ORGANS
PHOSPHOLIPIDS
PROTEINS
RATS
RODENTS
SACCHARIDES
SECRETION
STEROIDS
STEROLS
SYNTHESIS
TRIGLYCERIDES
VERTEBRATES