CHRONIC INGESTION OF BROMINATED VEGETABLE-OILS - ITS ACTION ON HEPATIC SECRETION AND CATABOLISM OF PLASMA-LIPOPROTEINS

We have previously reported that normal Wistar rats fed during 105 day s with standard laboratory chow, supplemented with 0.5g of brominated vegetable oil (olive, sunflower) per 100 g of diet showed a significan t increase of triglyceride and cholesterol content in both heart and l iver. This was accompanied by a significant decrease of plasma lipid l evels. Fluctuations in plasma triglyceride concentrations may be a res ult of either variations in the liver secretion rate of very low densi ty lipoprotein-triglyceride (VLDL-TG), or changes in their removal rat e by extrahepatic tissues or both. In the present work we have studied the contribution of both VLDL-TG secretion, and removal rates of plas ma TG in the decrease of plasma TG levels, in rats fed during 105 days with a standard laboratory chow supplemented with 0,5 g per 100 g of brominated vegetable oil. VLDL-TG secretion was estimated by measuring the accumulation of plasma TG following the injection of TRITON WR 13 39 and the removal rate of plasma TG by assaying plasma post-heparin l ipolytic total (PHLA) and hepatic (H-TGL) lipase activities. In additi on, the major lipid composition of plasma lipoprotein fractions were m easured. Results were compared to those of a control group fed a labor atory chow diet during the same period of time. Our results show a dec rease in both VLDL-TG secretion and plasma TG pool size accompanied by normal PHLA and H-TGL activities in animals fed the diet supplemented with brominated oils. However, the proportion of the major lipid comp onents of the plasma lipoproteins fractions were unchanged. This findi ng could indicate an impaired synthesis and/or secretion of VLDL-TG li poprotein by the liver. In summary, the toxicologic effects observed d uring chronic intake of diets supplemented with brominated oils, sugge st the need to undertake further biochemical studies of this food addi tive used in the manufacture of certain citrus flavored beverages.