Zur Verteilung körperfremder Fettsäuren im Tierkörper: Die Beteiligung der Erucasäure am Aufbau der Organ- und Depotfette nach längeren Gaben von Rapsöl

Physiopathological effects of rapeseed oil: a review

Rapeseed oil has a growth retarding effect in animals. Some investigators claim that the high content of erucic acid in rapeseed oil alone causes this effect, while others consider the low ratio saturated/monounsaturated fatty acids in rapeseed oil to be a contributory factor. Normally erucic acid is not found or occurs in traces in body fat, but when the diet contains rapeseed oil erucic acid is found in depot fat, organ fat and milk fat. Erucic acid is metabolized in vivo to oleic acid. The effects of rapeseed oil on reproduction and adrenals, testes, ovaries, liver, spleen, kidneys, blood, heart and skeletal muscles have been investigated. Fatty infiltration in the heart muscle cells has been observed in the species investigated. In long-term experiments in rats erucic acid produces fibrosis of the myocardium. Erucic acid lowers the respiratory capacity of the heart mitochondria. The reduction of respiratory capacity is roughly proportional to the content of erucic acid in the diet, and diminishes on continued administration of erucic acid. The lifespan of rats is the same on corn oil, soybean oil, coconut oil, whale oil and rapeseed oil diet. Rats fed a diet with erucic acid or other docosenoic acids showed a lowered tolerance to cold stress (+4 degrees C). In Sweden erucic acid constituted 3-4% of the average intake of calories up to 1970 compared with about 0.4% at present.

The beta-oxidative degradation of docosenoic acids to eicosenoic and octadecenoic acids in the rat

Methyl esters of monoenoic acids from rat tissue lipids were prepared and isolated by silver nitrate – silicic acid column chromatography and further separated according to chain length by preparative gas–liquid chromatography. Each monoenoic fraction was then oxidized for subsequent gas–liquid chromatography to distinguish isomeric intermediates of β-oxidation.Cetoleic acid (11-docosenoic), an isomer of erucic acid (13-docosenoic), was dagraded by the rat to gadoleic (9-eicosenoic) and 7-octadecenoic acids. By analogy, dietary erucic acid would contribute to the content of 11-eicosenoic and oleic (9-octadecenoic) acids in the tissue lipids.

FATTY ACID COMPOSITION AND GLYCERIDE STRUCTURE IN RATS FED RAPESEED OIL OR CORN OIL

The fatty acid compositions of liver, skin, abdominal fat, and residual degutted carcass from each of five rats fed diets containing corn or rapeseed oil for 21 weeks were determined by gas-liquid chromatography. Statistical analysis of the results showed no significant variations among rats or among cutaneous, abdominal, and carcass fats. In these fat depots, the proportions of fatty acids resembled those of the diet except for palmitic, palmitoleic, oleic, and erucic acids. Glyceride compositions of the body fats were in agreement with those predicted by Vander Wal's distribution theory.

FATTY ACID COMPOSITION AND GLYCERIDE STRUCTURE IN RATS FED RAPESEED OIL OR CORN OIL

The fatty acid compositions of liver, skin, abdominal fat, and residual degutted carcass from each of five rats fed diets containing corn or rapeseed oil for 21 weeks were determined by gas-liquid chromatography. Statistical analysis of the results showed no significant variations among rats or among cutaneous, abdominal, and carcass fats. In these fat depots, the proportions of fatty acids resembled those of the diet except for palmitic, palmitoleic, oleic, and erucic acids. Glyceride compositions of the body fats were in agreement with those predicted by Vander Wal's distribution theory.

STUDIES ON THE MECHANISMS BY WHICH ERUCIC ACID AFFECTS CHOLESTEROL METABOLISM: DISTRIBUTION OF ERUCIC ACID IN ADRENAL AND PLASMA LIPIDS

The effect of dietary erucic acid on the fatty acid composition of cholesterol ester, triglyceride and phospholipid fractions of rat adrenal, and plasma has been determined. Lipid classes were separated by chromatography on Florisil and their component fatty acids were determined by gas–liquid chromatography. Erucic acid was found in large amounts in adrenal cholesterol esters and in moderate amounts in adrenal and plasma triglycerides. Only small amounts were found in plasma cholesterol esters or the phospholipids of either adrenals or plasma. Eicosenoic acid was observed in some cases and the level of oleic acid was increased in most lipid classes of both tissues. This indicated partial stepwise oxidation of erucic acid. The increase in adrenal cholesterol caused by feeding erucic acid appears to be due primarily to accumulation of cholesterol erucate.

STUDIES ON THE MECHANISMS BY WHICH ERUCIC ACID AFFECTS CHOLESTEROL METABOLISM: DISTRIBUTION OF ERUCIC ACID IN ADRENAL AND PLASMA LIPIDS

The effect of dietary erucic acid on the fatty acid composition of cholesterol ester, triglyceride and phospholipid fractions of rat adrenal, and plasma has been determined. Lipid classes were separated by chromatography on Florisil and their component fatty acids were determined by gas–liquid chromatography. Erucic acid was found in large amounts in adrenal cholesterol esters and in moderate amounts in adrenal and plasma triglycerides. Only small amounts were found in plasma cholesterol esters or the phospholipids of either adrenals or plasma. Eicosenoic acid was observed in some cases and the level of oleic acid was increased in most lipid classes of both tissues. This indicated partial stepwise oxidation of erucic acid. The increase in adrenal cholesterol caused by feeding erucic acid appears to be due primarily to accumulation of cholesterol erucate.