TRANS FATTY ACIDS MODIFY NUTRITIONAL PARAMETERS AND TRIACYLGLYCEROL METABOLISM IN RATS: DIFFERENTIAL EFFECTS AT RECOMMENDED AND HIGH-FAT LEVELS.
BACKGROUND
there is still little evidence on the metabolic trans fatty acids (TFA) effects at recommended fat levels.


OBJECTIVE
to investigate the differential TFA effects on some nutritional parameters, TFA retention, and triacylglycerol (TAG) regulation in rats fed recommended and high-fat diets.


METHODS
male Wistar rats were fed (30 days) diets containing recommended (7%,w/w) or high-fat (20%,w/w) levels, supplemented or not with TFA (C7, C20, TFA7 and TFA20).


RESULTS
TFA7 (vs.C7) rats showed an increased body weight associated with higher fat pads and liver and serum TAG. The hypertriacylglyceridaemia was related to a decreased muscle LPL activity, while the higher hepatic TAG content was associated with both an increased SREBP-1c gene expression and ACC activity, and a reduced CPT-Ia gene expression. The TFA20 diet did not potentiate the higher body weight, fat pads and TAG levels induced by the C20 diet. Although the hepatic TAG-secretion rate (TAG-SR) increased by TFA20 vs. C20, the same triacylglyceridaemia was associated with a compensatory increase of the adipose tissue LPL activity. The attenuated hepatic TAG accretion in TFA20 was related to an increase of TAG-SR and to a lower increase of SREBP-1c and SCD1 mRNA expressions, paralleled to a relative decrease of SCD1 index and ACC activity.


CONCLUSIONS
TFA alters nutritional parameters and lipid metabolism in rats. However, different responses to the TFA on TAG levels and their regulation were observed between rats fed recommended and high-fat diets. These divergences might be related to different tissue TFA retentions and rumenic acid bioconversion.
Cátedra Bromatología y Nutrición. Facultad de Bioquímica y Ciencias Biológicas. Universidad Nacional del Litoral. Ciudad Universitaria, Santa Fe.. cbernal@fbcb.unl.edu.ar.
Paola Guadalupe
PG
Illesca
Cátedra Bromatología y Nutrición. Facultad de Bioquímica y Ciencias Biológicas. Universidad Nacional del Litoral. Ciudad Universitaria, Santa Fe. Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Santa Fe (Argentina).. cbernal@fbcb.unl.edu.ar.
Jimena Verónica
JV
Lavandera
Cátedra Bromatología y Nutrición. Facultad de Bioquímica y Ciencias Biológicas. Universidad Nacional del Litoral. Ciudad Universitaria, Santa Fe. Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Santa Fe (Argentina).. cbernal@fbcb.unl.edu.ar.
Carolina Daniela
CD
Gerstner
Cátedra Bromatología y Nutrición. Facultad de Bioquímica y Ciencias Biológicas. Universidad Nacional del Litoral. Ciudad Universitaria, Santa Fe.. cbernal@fbcb.unl.edu.ar.
Marcela Aída
MA
González
Cátedra Bromatología y Nutrición. Facultad de Bioquímica y Ciencias Biológicas. Universidad Nacional del Litoral. Ciudad Universitaria, Santa Fe. Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Santa Fe (Argentina).. cbernal@fbcb.unl.edu.ar.
Claudio Adrián
CA
Bernal
D000821:Animal Feed / Q000032:analysis; D000818:Animals; D004041:Dietary Fats; D002149:Energy Intake; D015870:Gene Expression; D050356:Lipid Metabolism; D008099:Liver / Q000378:metabolism; D008297:Male; D009753:Nutritive Value; D051381:Rats; D044242:Trans Fatty Acids / Q000378:metabolism*; D014280:Triglycerides / Q000097:blood / Q000378:metabolism*
D004041:Dietary Fats; D044242:Trans Fatty Acids; D014280:Triglycerides