Contrasting effects of t10,c12- and c9,t11-conjugated linoleic acid isomers on the fatty acid profiles of mouse liver lipids.
The purpose of this study was to examine the effects of two purified isomers of CLA (c9,t11-CLA and t10,c12-CLA) on the weights and FA compositions of hepatic TG, phospholipids, cholesterol esters, and FFA. Eight-week-old female mice (n = 6/group) were fed either a control diet or diets supplemented with 0.5% c9,t11-CLA or t10,c12-CLA isomers for 8 wk. Weights of liver total lipids and those of individual lipid fractions did not differ between the control and the c9,t11-CLA groups. Livers from animals fed the t10, c12-CLA diet contained four times more lipids than those of the control group; this was mainly due to an increase in the TG fractions (fivefold), but cholesterol (threefold), cholesterol esters (threefold), and FFA (twofold) were also significantly increased. Although c9,t11-CLA did not significantly alter the weights of liver lipids when compared with the control group, its intake was associated with significant reductions in the weight percentage (wt% of total FAME) of 18:1n-9 and 18:1n-7 in the TG fraction and with significant increases in the weight percentage of 18:2n-6 in the TG, cholesterol ester, and phospholipid fractions. On the other hand, t10,c12-CLA intake was linked with a significant increase in the weight percentage of 18:1n-9 and a decrease in that of 18:2n-6 in all lipid fractions. These changes may be the result of alterations in the activity of delta9-desaturase (stearoyl CoA desaturase) and the enzymes involved in the metabolism of 18:2n-6. Thus, the two isomers differed not only in their effects on the weights of total liver lipids and lipid fractions but also on the FA profile of the lipid fractions.
Kelley
D S
DS
Western Human Nutrition Research Center, ARS, USDA, Department of Nutrition, University of California, Davis, California 95616, USA. dkelley@whnrc.usda.gov
Bartolini
G L
GL
Warren
J M
JM
Simon
V A
VA
Mackey
B E
BE
Erickson
K L
KL
D000818:Animals; D002788:Cholesterol Esters / Q000032:analysis / Q000737:chemistry; D005227:Fatty Acids / Q000032:analysis* / Q000737:chemistry; D005260:Female; D008041:Linoleic Acids / Q000737:chemistry / Q000494:pharmacology*; D008055:Lipids / Q000032:analysis* / Q000737:chemistry; D008099:Liver / Q000737:chemistry*; D051379:Mice; D008810:Mice, Inbred C57BL; D010743:Phospholipids / Q000032:analysis / Q000737:chemistry; D013237:Stereoisomerism; D014280:Triglycerides / Q000032:analysis / Q000737:chemistry
D002788:Cholesterol Esters; D005227:Fatty Acids; D008041:Linoleic Acids; D008055:Lipids; D010743:Phospholipids; D014280:Triglycerides