Effects of dietary corn and olive oil versus coconut fat on biliary cholesterol secretion in rats

• Published in: International journal for vitamin and nutrition research Vol. 64; no. 1; pp. 75 - 80
• Main Authors: Smit, M.J, Wolters, H, Temmerman, A.M, Kuipers, F, Beynen, A.C, Vonk, R.J
• Format: Journal Article
• Language: English
• Published: Switzerland 1994
• Subjects: Animals; bile; Bile - metabolism; bile acids; blood plasma; Cell Membrane - metabolism; chemical composition; cholesterol; Cholesterol - metabolism; Coconut Oil; corn oil; Corn Oil - chemistry; Corn Oil - pharmacology; diet; Dietary Fats - pharmacology; Dietary Fats, Unsaturated - pharmacology; experimental diets; Fatty Acids - analysis; flow; fluidity; lipids; liver; Liver - metabolism; Male; Olive Oil; Plant Oils - chemistry; Plant Oils - pharmacology; plasma membrane; Rats; Rats, Wistar; secretion
• ISSN: 0300-9831

We have studied the effects of dietary corn and olive oil versus coconut fat on bile formation and fluidity of hepatic plasma membranes in rats. After 4 weeks of feeding the purified diets containing 9% (w/w) of the test fats, there was no difference in plasma cholesterol concentration between the dietary groups. The amount of free and esterified cholesterol in the liver was significantly higher in rats fed either corn oil or olive oil as compared with coconut fat. In the rats fed olive oil, but not in those fed corn oil this was associated with lower rates of biliary phospholipid excretion. Bile flow was not differently influenced by the three dietary fats. Hepatic plasma membranes of the rats fed corn or olive oil contained more cholesterol and less phospholipids than those on coconut fat, which was, however, not accompanied by changes in fluidity of the membranes. These results indicate that in rats the type of dietary fat can induce considerable changes in hepatic cholesterol metabolism without affecting plasma cholesterol concentrations, and without consistent effects on biliary cholesterol secretion.