Early and prolonged intake of partially hydrogenated fat alters the expression of genes in rat adipose tissue.

OBJECTIVE

Our previous study indicated that partially hydrogenated fat (PHF) diets, rich in trans-isomers, alter plasma lipids and increase the lipogenesis rate on adipose tissue in rats at a young age. In the present study we investigated the effects of dietary PHF on the expression of genes associated with glucose and lipid metabolism in rat adipose tissue.

METHODS

Female Wistar rats were fed normolipidic diets containing PHF (rich in trans-fatty acids and poor in polyunsaturated fatty acids [PUFAs]), soy oil (rich in omega-6 PUFAs), and fish oil (rich in omega-3 PUFAs) during gestation and lactation; young male pups were fed the same diets from weaning until 120 d of life. The mRNA expression of peroxisome proliferator-activated receptor-gamma, tumor necrosis factor-alpha, resistin, adiponectin, and leptin were analyzed in retroperitoneal adipose tissue (RET) using real time polymerase chain reaction.

RESULTS

The PHF group showed the highest triacylglycerol, glucose, and insulin levels and the lowest plasma adiponectin level. The RET of PHF incorporated trans-fatty acids, whereas fish oil and soy oil groups had increased omega-3 and omega-6 PUFAs, respectively. In the RET the PHF group had the highest resistin and tumor necrosis factor-alpha levels and the lowest adiponectin and peroxisome proliferator-activated receptor-gamma gene expressions, whereas the fish oil group had the highest peroxisome proliferator-activated receptor-gamma and the lowest leptin gene expression.

CONCLUSION

Prolonged intake of PHF has a negative effect on the expression of genes in RET when compared with diets with omega-6 and omega-3 PUFAs. These changes may be an effect of the smaller proportions of PUFAs in this fat, instead of being only caused by trans-fatty acids.