Tags

Type your tag names separated by a space and hit enter

Regulation of guinea pig plasma low density lipoprotein kinetics by dietary fat saturation.
J Lipid Res. 1992 Jan; 33(1):97-109.JL

Abstract

Dietary fat saturation has been shown to affect hepatic apoB/E receptor expression and to modify low density lipoprotein (LDL) composition and density in guinea pigs. The current studies were designed to investigate the independent and interactive effects of dietary fat saturation alterations in apoB/E receptor expression and LDL composition on in vivo LDL turnover kinetics, both receptor-mediated and receptor-independent. Guinea pigs were fed semi-purified diets containing 15% fat, either polyunsaturated corn oil (CO), monounsaturated olive oil (OL), or saturated lard, and injected with radioiodinated LDL isolated from animals fed the homologous diet. Blood samples were obtained over 33 h to determine apoLDL fractional catabolic rates (FCR) and flux rates. Compared to animals fed OL- or lard-based diets, intake of the CO-based diet resulted in a 50% decrease in LDL apoB pool size associated with a twofold increase in receptor-mediated FCR (P less than 0.001) and a 28% decrease in flux rate (P less than 0.05). Maximal LDL binding capacity of hepatic apoB/E receptors, determined in vitro, was twofold higher for animals fed the CO-based diet compared to guinea pigs fed the OL- and lard-based diets (P less than 0.01). There was a significant correlation between hepatic apoB/E receptor number and in vivo receptor-mediated LDL FCR (r = 0.987). Significant differences in LDL turnover were related to the source of LDL. When injected into animals fed a nonpurified commercial diet, the smaller, cholesteryl ester-depleted LDL isolated from animals fed the CO-based diet had a twofold higher FCR compared to larger LDLs from guinea pigs fed the OL- and lard-based diets, which had similar turnover rates. When LDL from animals fed the commercial diet was radiolabeled and injected into animals fed the three types of dietary fat, significant differences in LDL turnover were observed in the order CO greater than lard greater than OL, suggesting that intravascular processing and tissue uptake of the smaller LDL from animals fed the commercial diet varies depending on the dietary fat saturation fed to the recipient animals. These studies demonstrate that guinea pigs fed polyunsaturated fat diets lower plasma LDL levels in part by an increase in apoB/E receptor-mediated fractional LDL turnover and a decrease in apoLDL flux. In addition, fat saturation alters LDL composition and size which independently affect LDL turnover rates in vivo.

Authors+Show Affiliations

Department of Nutrition and Food Science, University of Arizona, Tucson 85721.No affiliation info availableNo affiliation info available

Pub Type(s)

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

Language

eng

PubMed ID

1313073

Citation

Fernandez, M L., et al. "Regulation of Guinea Pig Plasma Low Density Lipoprotein Kinetics By Dietary Fat Saturation." Journal of Lipid Research, vol. 33, no. 1, 1992, pp. 97-109.
Fernandez ML, Lin EC, McNamara DJ. Regulation of guinea pig plasma low density lipoprotein kinetics by dietary fat saturation. J Lipid Res. 1992;33(1):97-109.
Fernandez, M. L., Lin, E. C., & McNamara, D. J. (1992). Regulation of guinea pig plasma low density lipoprotein kinetics by dietary fat saturation. Journal of Lipid Research, 33(1), 97-109.
Fernandez ML, Lin EC, McNamara DJ. Regulation of Guinea Pig Plasma Low Density Lipoprotein Kinetics By Dietary Fat Saturation. J Lipid Res. 1992;33(1):97-109. PubMed PMID: 1313073.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Regulation of guinea pig plasma low density lipoprotein kinetics by dietary fat saturation. AU - Fernandez,M L, AU - Lin,E C, AU - McNamara,D J, PY - 1992/1/1/pubmed PY - 1992/1/1/medline PY - 1992/1/1/entrez SP - 97 EP - 109 JF - Journal of lipid research JO - J Lipid Res VL - 33 IS - 1 N2 - Dietary fat saturation has been shown to affect hepatic apoB/E receptor expression and to modify low density lipoprotein (LDL) composition and density in guinea pigs. The current studies were designed to investigate the independent and interactive effects of dietary fat saturation alterations in apoB/E receptor expression and LDL composition on in vivo LDL turnover kinetics, both receptor-mediated and receptor-independent. Guinea pigs were fed semi-purified diets containing 15% fat, either polyunsaturated corn oil (CO), monounsaturated olive oil (OL), or saturated lard, and injected with radioiodinated LDL isolated from animals fed the homologous diet. Blood samples were obtained over 33 h to determine apoLDL fractional catabolic rates (FCR) and flux rates. Compared to animals fed OL- or lard-based diets, intake of the CO-based diet resulted in a 50% decrease in LDL apoB pool size associated with a twofold increase in receptor-mediated FCR (P less than 0.001) and a 28% decrease in flux rate (P less than 0.05). Maximal LDL binding capacity of hepatic apoB/E receptors, determined in vitro, was twofold higher for animals fed the CO-based diet compared to guinea pigs fed the OL- and lard-based diets (P less than 0.01). There was a significant correlation between hepatic apoB/E receptor number and in vivo receptor-mediated LDL FCR (r = 0.987). Significant differences in LDL turnover were related to the source of LDL. When injected into animals fed a nonpurified commercial diet, the smaller, cholesteryl ester-depleted LDL isolated from animals fed the CO-based diet had a twofold higher FCR compared to larger LDLs from guinea pigs fed the OL- and lard-based diets, which had similar turnover rates. When LDL from animals fed the commercial diet was radiolabeled and injected into animals fed the three types of dietary fat, significant differences in LDL turnover were observed in the order CO greater than lard greater than OL, suggesting that intravascular processing and tissue uptake of the smaller LDL from animals fed the commercial diet varies depending on the dietary fat saturation fed to the recipient animals. These studies demonstrate that guinea pigs fed polyunsaturated fat diets lower plasma LDL levels in part by an increase in apoB/E receptor-mediated fractional LDL turnover and a decrease in apoLDL flux. In addition, fat saturation alters LDL composition and size which independently affect LDL turnover rates in vivo. SN - 0022-2275 UR - https://www.unboundmedicine.com/medline/citation/1313073/Regulation_of_guinea_pig_plasma_low_density_lipoprotein_kinetics_by_dietary_fat_saturation_ L2 - https://linkinghub.elsevier.com/retrieve/pii/S0022-2275(20)41887-5 DB - PRIME DP - Unbound Medicine ER -