Effect of dietary cholesterol and high fat on ceramide concentration in rat tissues.
OBJECTIVE
Recent studies have indicated that plasma sphingomyelin levels and sphingomyelinase activity are risk factors for atherosclerosis. Therefore, it is suggested that ceramides, which are hydrolyzed products of sphingomyelin and a biologically active lipid causing apoptosis in a variety of cells, have an important role in the incidence of atherosclerosis. In this study, we examined whether cholesterol- and fat-enriched diets, which are causes of atherosclerosis, affect ceramide metabolism. In addition, we found a relation among lipid markers of atherosclerosis such as cholesterol, triacylglycerol, and ceramide concentrations.


METHODS
Male Wistar rats were fed a diet supplemented with 1% cholesterol or 30% high-fat diet for 8 wk. Tissue ceramide levels were analyzed using electrospray tandem mass spectrometry.


RESULTS
The major ceramides in plasma and the liver were C24:0 and C24:1. The major ceramides in adipose tissues were C16:0 and C24:0. Therefore, the ceramide composition of the adipose tissues was different from that of plasma and the liver. In addition, total ceramide levels in plasma and the adipose tissues of rats fed cholesterol were higher than those in the control group.


CONCLUSIONS
The accumulation of cholesterol caused an increase in ceramides, which might be a new risk factor for atherosclerosis.
Ichi
Ikuyo
I
Department of Food Science and Nutrition, Nara Women's University, Nara, Japan.
Nakahara
Kayoko
K
Kiso
Kaori
K
Kojo
Shosuke
S
D000818:Animals; D050197:Atherosclerosis / Q000097:blood*; D002518:Ceramides / Q000032:analysis / Q000378:metabolism*; D002784:Cholesterol / Q000097:blood*; D002791:Cholesterol, Dietary / Q000008:administration & dosage*; D004041:Dietary Fats / Q000008:administration & dosage*; D008297:Male; D011897:Random Allocation; D051381:Rats; D017208:Rats, Wistar; D012307:Risk Factors; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods
D002518:Ceramides; D002791:Cholesterol, Dietary; D004041:Dietary Fats; D002784:Cholesterol