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The influence of dietary saturated and unsaturated fat on hepatic cholesterol metabolism and the biliary excretion of chylomicron cholesterol in the rat.
Biochim Biophys Acta. 1998 Feb 16; 1390(2):134-48.BB

Abstract

The biliary excretion of [3H] cholesterol carried in chylomicrons derived from palm oil (rich in long chain saturated fatty acids), olive oil (rich in monounsaturated fatty acids) or corn oil (rich in n-6 polyunsaturated fatty acids was studied in vivo in rats fed the corresponding oil in the diet for 21 days. The secretion of radioactivity into bile as both bile acids and unesterified cholesterol was significantly slower in the animals fed palm oil as compared to those given olive or corn oil, indicating that dietary saturated fat retards the excretion of cholesterol from the diet as compared to mono- or n-6 polyunsaturated fat. In order to investigate the mechanisms underlying these differences, the influence of the three high fat diets on cholesterol esterification, cholesteryl ester hydrolysis and bile acid synthesis in the liver and on biliary lipid output were also measured. The ratio of cholesterol esterification to cholesteryl ester hydrolysis was markedly raised in the olive and corn oil-fed as compared to palm oil-fed animals. Biliary cholesterol secretion was higher in corn oil-fed rats than in those fed olive or palm oil or a low fat diet, and this was associated with a markedly increased lithogenic index in these animals. The activity of cholesterol 7alpha hydroxylase was higher in the olive and corn oil-fed than in the palm oil-fed animals, although the expression of mRNA for the enzyme was increased only in the olive oil diet group. After 20 h biliary drainage, the rate of bile acid secretion into bile was increased in the rats fed olive and corn oil rather than to palm oil. These findings indicate that feeding rats mono- or n-6 polyunsaturated as compared to saturated fat in the diet promotes the storage of cholesteryl ester in the liver and leads to increased bile acid synthesis, resulting in the more rapid excretion of cholesterol originating from the diet via the bile.

Authors+Show Affiliations

Istituto Superiore di Sanita, Laboratorio di of Metabolismo e Biochimica Patologica, Viale Regina Elena 299, 00161 Roma, Italy.No affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

9507091

Citation

Bravo, E, et al. "The Influence of Dietary Saturated and Unsaturated Fat On Hepatic Cholesterol Metabolism and the Biliary Excretion of Chylomicron Cholesterol in the Rat." Biochimica Et Biophysica Acta, vol. 1390, no. 2, 1998, pp. 134-48.
Bravo E, Flora L, Cantafora A, et al. The influence of dietary saturated and unsaturated fat on hepatic cholesterol metabolism and the biliary excretion of chylomicron cholesterol in the rat. Biochim Biophys Acta. 1998;1390(2):134-48.
Bravo, E., Flora, L., Cantafora, A., De Luca, V., Tripodi, M., Avella, M., & Botham, K. M. (1998). The influence of dietary saturated and unsaturated fat on hepatic cholesterol metabolism and the biliary excretion of chylomicron cholesterol in the rat. Biochimica Et Biophysica Acta, 1390(2), 134-48.
Bravo E, et al. The Influence of Dietary Saturated and Unsaturated Fat On Hepatic Cholesterol Metabolism and the Biliary Excretion of Chylomicron Cholesterol in the Rat. Biochim Biophys Acta. 1998 Feb 16;1390(2):134-48. PubMed PMID: 9507091.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - The influence of dietary saturated and unsaturated fat on hepatic cholesterol metabolism and the biliary excretion of chylomicron cholesterol in the rat. AU - Bravo,E, AU - Flora,L, AU - Cantafora,A, AU - De Luca,V, AU - Tripodi,M, AU - Avella,M, AU - Botham,K M, PY - 1998/5/2/pubmed PY - 1998/5/2/medline PY - 1998/5/2/entrez SP - 134 EP - 48 JF - Biochimica et biophysica acta JO - Biochim. Biophys. Acta VL - 1390 IS - 2 N2 - The biliary excretion of [3H] cholesterol carried in chylomicrons derived from palm oil (rich in long chain saturated fatty acids), olive oil (rich in monounsaturated fatty acids) or corn oil (rich in n-6 polyunsaturated fatty acids was studied in vivo in rats fed the corresponding oil in the diet for 21 days. The secretion of radioactivity into bile as both bile acids and unesterified cholesterol was significantly slower in the animals fed palm oil as compared to those given olive or corn oil, indicating that dietary saturated fat retards the excretion of cholesterol from the diet as compared to mono- or n-6 polyunsaturated fat. In order to investigate the mechanisms underlying these differences, the influence of the three high fat diets on cholesterol esterification, cholesteryl ester hydrolysis and bile acid synthesis in the liver and on biliary lipid output were also measured. The ratio of cholesterol esterification to cholesteryl ester hydrolysis was markedly raised in the olive and corn oil-fed as compared to palm oil-fed animals. Biliary cholesterol secretion was higher in corn oil-fed rats than in those fed olive or palm oil or a low fat diet, and this was associated with a markedly increased lithogenic index in these animals. The activity of cholesterol 7alpha hydroxylase was higher in the olive and corn oil-fed than in the palm oil-fed animals, although the expression of mRNA for the enzyme was increased only in the olive oil diet group. After 20 h biliary drainage, the rate of bile acid secretion into bile was increased in the rats fed olive and corn oil rather than to palm oil. These findings indicate that feeding rats mono- or n-6 polyunsaturated as compared to saturated fat in the diet promotes the storage of cholesteryl ester in the liver and leads to increased bile acid synthesis, resulting in the more rapid excretion of cholesterol originating from the diet via the bile. SN - 0006-3002 UR - https://www.unboundmedicine.com/medline/citation/9507091/The_influence_of_dietary_saturated_and_unsaturated_fat_on_hepatic_cholesterol_metabolism_and_the_biliary_excretion_of_chylomicron_cholesterol_in_the_rat_ L2 - https://linkinghub.elsevier.com/retrieve/pii/S0005-2760(97)00174-4 DB - PRIME DP - Unbound Medicine ER -