FEEDING TRANS-FATTY-ACIDS TO RATS HAS NO EFFECT ON THE INTESTINAL UPTAKE OF GLUCOSE, FATTY-ACIDS OR CHOLESTEROL

Trans fatty acids are produced in the manufacture of margarine, and th ese hydrogenated fatty acids may have a deleterious effect on the redu ction in fasting levels of serum cholesterol anticipated from the feed ing of cis polyunsaturated fatty acids. We undertook this study in rat s to test the effect of feeding trans fatty acids on the intestinal up take of glucose, fatty acids and cholesterol. Adult female Wistar rats were fed for 2 weeks semisynthetic, isocaloric diets containing no ol eic acid (18:1), cis 18:1 or trans 18:1. There was no difference betwe en the three dietary groups in the animals' food consumption or body w eight gain. Rats fed trans 18:1 had an approximately 20% decline in th e total weight of the ileum as compared with controls fed no 18:1, and therefore there was also a decline in the percentage of the ileal tis sue comprised of mucosa. When comparing rats fed trans 18:1 with those fed cis 18:1 or no 18:1, there was no difference in the uptake of var ying concentrations of D-glucose when expressed as nmol.100 mg tissue( -1).min(-1) or nmol.100 mg mucosa(-1).min(-1) forjejunum or for ileum. Also, there was no difference in the value of the maximal transport r ate (V-max), Michaelis constant (K-m), or the contribution of passive uptake of glucose assessed with L-glucose. There was no diet-associate d change in the jejunal or ileal uptake of a medium-chain length fatty acid (lauric acid), a long-chain length saturated fatty acid (palmiti c acid), a monounsaturated fatty acid (oleic acid), two polyunsaturate d fatty acids (linoleic and linolenic acids), or cholesterol. Thus, we conclude that 2 weeks' feeding of trans fatty acid to rats has no inf luence on the jejunal or ileal uptake of glucose, fatty acids or chole sterol.