Effect of feeding pattern on fatty acid oxidation by rat liver slices

These studies were undertaken to further characterize and explain the differences in hepatic fatty acid metabolism between lean and obese Zucker rats. It was shown that the rate of palmitate or octanoate oxidation and the inhibition of palmitate oxidation by malonyl CoA in mitochondria isolated from lean and obese Zucker rats were similar. Cytochrome oxidase activity was similar in lean and obese rat livers. It was found that the addition of cytosol from the obese rat liver inhibited palmitate oxidation by 20-30% in mitochondria isolated from lean or obese rat livers and thus reproduced the conditions observed in the intact cell. Increased concentrations of metabolites such as malonyl CoA and glycerophosphate in the liver of the obese rat are likely contributors to this inhibitory effect. These results are extrapolated to the intact cell and suggest that decreased hepatic fatty acid oxidation in the obese rat can be accounted for by cytosolic influences on the mitochondria. The decreased rate of fatty acid oxidation observed in the intact hepatocyte or perfused liver cannot be explained by a defect in the capacity of mitochondria to oxidize substrate or by a decrease in mitochondrial number in the obese rat liver.

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Lipid Metabolism and Nutrigenomics – Impact of Sesame Lignans on Gene Expression Profiles and Fatty Acid Oxidation in Rat Liver

Forum of Nutrition - Food Factors for Health Promotion ◽

10.1159/000212735 ◽

2009 ◽

pp. 10-24 ◽

Cited By ~ 13

Author(s):

Takashi Ide ◽

Yasutaka Nakashima ◽

Hiroshi Iida ◽

Satoko Yasumoto ◽

Masumi Katsuta

Keyword(s):

Gene Expression ◽

Fatty Acid ◽

Lipid Metabolism ◽

Fatty Acid Oxidation ◽

Rat Liver ◽

Expression Profiles ◽

Gene Expression Profiles ◽

Acid Oxidation ◽

Sesame Lignans

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Effects of milk diets containing beef tallow or coconut oil on the fatty acid metabolism of liver slices from preruminant calves

British Journal Of Nutrition ◽

10.1017/s0007114500001586 ◽

2000 ◽

Vol 84 (3) ◽

pp. 309-318 ◽

Cited By ~ 14

Author(s):

Benoît Graulet ◽

Dominique Gruffat-Mouty ◽

Denys Durand ◽

Dominique Bauchart

Keyword(s):

Fatty Acid ◽

Fatty Acid Oxidation ◽

Beef Tallow ◽

Neutral Lipids ◽

Lipid Production ◽

Coconut Oil ◽

Acid Oxidation ◽

Milk Diet ◽

Liver Slices ◽

Triacylglycerol Accumulation

Coconut oil (CO) induces a triacylglycerol infiltration in the hepatocytes of preruminant calves when given as the sole source of fat in the milk diet over a long-term period. Metabolic pathways potentially involved in this hepatic triacylglycerol accumulation were studied by in vitro methods on liver slices from preruminant Holstein × Friesian male calves fed a conventional milk diet containing CO (n 5) or beef tallow (BT, n 5) for 19 d. Liver slices were incubated for 12 h in the presence of 0·8 mM-[14C] oleate or -[14C] laurate added to the medium. Fatty acid oxidation was determined by measuring the production of CO2 (total oxidation) and acid-soluble products (partial oxidation). Production of CO2 was 1·7–3·6-fold lower (P 0·0490) and production of acid-soluble products tended to be lower (P = 0·0625) in liver slices of CO- than BT-fed calves. Fatty acid esterification as neutral lipids was 2·6– to 3·1–fold higher (P = 0·0088) in liver slices prepared from calves fed the CO diet compared with calves fed the BT diet. By contrast with what occurs in the liver of rats fed CO, the increase in neutral lipid production did not stimulate VLDL secretion by the hepatocytes of calves fed with CO, leading to a triacylglycerol accumulation in the cytosol. It could be explained by the reduction of fatty acid oxidation favouring esterification in the form of triacylglycerols, in association with a limited availability of triacylglycerols and/or apolipoprotein B for VLDL packaging and subsequent secretion.

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