The mechanism of dietary cholesterol effects on lipids metabolism in rats.
BACKGROUND
Cholesterol administration has been reported to influence hepatic lipid metabolism in rats. In the present study, the effect of dietary cholesterol on hepatic activity and mRNA expression of the enzymes involved in lipid metabolism were investigated. Fourteen male Wistar rats were randomly divided into 2 groups and fed 1% cholesterol or cholesterol free AIN76 diets for 4 weeks.


RESULTS
The serum triglyceride and high density lipoprotein cholesterol levels were significantly decreased but the total cholesterol and non high density lipoprotein cholesterol levels were significantly increased in the cholesterol-fed rats compared with the control rats. And the concentrations of the hepatic total cholesterol and triglyceride increased about 4-fold and 20-fold separately by dietary cholesterol. The activities of hepatic malic enzyme, glucose-6-phosphate dehydrogenase, fatty acid synthase, phosphatidate phophatase and carnitine palmitoyl transferase were depressed by the cholesterol feeding (40%, 70%, 50%, 15% and 25% respectively). The results of mRNA expression showed that fatty acid synthase, carnitine palmitoyl transferase 1, carnitine palmitoyl transferase 2, and HMG-CoA reductase were down-regulated (35%, 30%, 50% and 25% respectively) and acyl-CoA: cholesterol acyltransferase and cholesterol 7alpha-hydroxylase were up regulated (1.6 and 6.5 folds) in liver by the cholesterol administration.


CONCLUSIONS
The dietary cholesterol increased the triglyceride accumulation in liver, but did not stimulate the activity and the gene expression of hepatic enzymes related to triglyceride and fatty acid biosynthesis.
Wang
Yu-Ming
YM
College of Food Science and Engineering, Ocean University of China, Qingdao, China.
Zhang
Bei
B
Xue
Yong
Y
Li
Zhao-Jie
ZJ
Wang
Jing-Feng
JF
Xue
Chang-Hu
CH
Yanagita
Teruyoshi
T
D000821:Animal Feed; D000818:Animals; D001786:Blood Glucose / Q000378:metabolism; D002334:Carnitine O-Palmitoyltransferase / Q000378:metabolism; D002784:Cholesterol / Q000737:chemistry / Q000378:metabolism; D005227:Fatty Acids / Q000737:chemistry; D050356:Lipid Metabolism; D008055:Lipids / Q000737:chemistry*; D008099:Liver / Q000378:metabolism; D008297:Male; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D002785:Sterol O-Acyltransferase / Q000378:metabolism; D014280:Triglycerides / Q000737:chemistry
D001786:Blood Glucose; D005227:Fatty Acids; D008055:Lipids; D012333:RNA, Messenger; D014280:Triglycerides; D002784:Cholesterol; D002334:Carnitine O-Palmitoyltransferase; D002785:Sterol O-Acyltransferase