[Urinary excretion of glucuronic and hippuric acids in rats ingesting heated linseed oil].
Nutritionally harmful substances are formed when edible vegetable oils are heated (cyclization, polymerization of unsaturated fatty acids, ...). How are these substances metabolized in animals? This work is a first attempt to experiment if these altered fatty acids or their metabolites are excreted as conjugated compounds in the urine. Weaning rats (weighing 45 g) were divided into 3 groups of 9 animals each. They received balanced diets containing 10 p. 100 by weight of lipids. In the first group, the dietary of lipids was linseed oil which had been heated for 12 hours at 275 degrees C under nitrogen (group HC275); in the second group, the linseed oil had been heated 100 hours at 200 degrees C in presence of air (group HC200). These two groups of animals were fed ad libitum. The control group (group HF) was fed a diet containing fresh linseed oil and its food consumption was restricted to the quantity eated by the HC275 group (pair feeding). Urines were collected daily from the 8th to the 15th day of experiment and pooled for each rat. Hippuric acid and glucuronic acid contents were determined in these urines. During this period the hippuric acid excretion in HC275 and HC200 groups is twice as high as in HF group (32, 35 and 17 mumoles respectively). On the other hand urinary excretion of glucoronic acid is 8 times higher in HC275 and 3 times in HC200 than in HF (2214, 739 and 269 mumoles respectively). Hippuric acid excretion is very small as compared to that of glucuronic acid. Therefore it seems that most of the compounds formed during heating of the oil or their metabolites are excreted as glucoronic acid conjugates.
D000388:Air; D000818:Animals; D001835:Body Weight; D003500:Cyclization; D004032:Diet; D005965:Glucuronates / Q000652:urine*; D006626:Hippurates / Q000652:urine*; D006358:Hot Temperature; D008042:Linolenic Acids; D008043:Linseed Oil / Q000009:adverse effects / Q000378:metabolism; D008297:Male; D009584:Nitrogen; D010084:Oxidation-Reduction; D051381:Rats
D005965:Glucuronates; D006626:Hippurates; D008042:Linolenic Acids; D008043:Linseed Oil; D009584:Nitrogen
Excrétion urinaire d'acide clucuronique et d'acide hippurique, chez le rat ingérant des huiles de lin chauffées