Effect of corn and coconut oil-containing diets with and without cholesterol on high density lipoprotein apoprotein A-I metabolism and hepatic apoprotein A-I mRNA levels in cebus monkeys.
The mechanism(s) by which diets containing corn or coconut oil (31% of energy as fat) totally free of cholesterol or with 0.1% added cholesterol by weight (0.3 mg/kcal) affect plasma high density lipoprotein cholesterol (HDL-C), apoprotein (apo) A-I levels, apo A-I kinetics, and hepatic apo A-I mRNA concentrations were investigated in 26 cebus monkeys. Coconut oil-fed monkeys had elevated levels of plasma total cholesterol (217%), very low density lipoprotein plus low density lipoprotein cholesterol (331%), HDL-C (159%), and apo A-I (117%) compared with corn oil-fed animals. Although the addition of cholesterol to the corn oil diet significantly increased these parameters, no such effects were seen when cholesterol was added to the coconut-oil diet. Both the type of fat and cholesterol in the diet significantly affected HDL apo A-I metabolism by decreasing apo A-I fractional catabolic rate and increasing apo A-I production rate in the coconut oil-fed groups. The decrease in apo A-I fractional catabolic rate in the coconut oil-fed animals was also associated with an increase in the HDL core lipid to surface ratio. Liver apo A-I mRNA abundance was elevated in the coconut oil-fed groups; however, dietary cholesterol had no affect on these levels. The lack of parallel effects of dietary fat and cholesterol on apo A-I production rate and liver apo A-I mRNA levels suggests that the increase in the apo A-I production rate observed in the coconut oil-fed groups resulted from the fat-induced rise in liver apo A-I mRNA abundance, whereas the cholesterol-induced rise in the apo A-I production rate resulted from a mechanism other than changes in liver apo A-I mRNA levels.
Stucchi
A F
AF
Department of Clinical Sciences, University of Lowell, MA 01854.
Hennessy
L K
LK
Vespa
D B
DB
Weiner
E J
EJ
Osada
J
J
Ordovas
J M
JM
Schaefer
E J
EJ
Nicolosi
R J
RJ
D000818:Animals; D016632:Apolipoprotein A-I / Q000235:genetics / Q000378:metabolism*; D002428:Cebus; D002791:Cholesterol, Dietary / Q000494:pharmacology*; D000074263:Coconut Oil; D003314:Corn Oil / Q000008:administration & dosage* / Q000494:pharmacology; D004042:Dietary Fats, Unsaturated / Q000032:analysis / Q000494:pharmacology*; D005227:Fatty Acids / Q000032:analysis; D008075:Lipoproteins, HDL / Q000737:chemistry / Q000378:metabolism*; D008099:Liver / Q000378:metabolism; D008297:Male; D010938:Plant Oils / Q000008:administration & dosage* / Q000494:pharmacology; D012333:RNA, Messenger / Q000378:metabolism
D016632:Apolipoprotein A-I; D002791:Cholesterol, Dietary; D004042:Dietary Fats, Unsaturated; D005227:Fatty Acids; D008075:Lipoproteins, HDL; D010938:Plant Oils; D012333:RNA, Messenger; D003314:Corn Oil; D000074263:Coconut Oil