Abstract: Objective To elucidate the effects of resistin with different levels on serum free fatty acid (FFA) in intrinsic and extrinsic hyper-resistin models. Methods The extrinsic hyper-resistin models were established by infusion of rat recombinant resistin through the tail vein and defined as resistin group (RE group, n=8); the normal saline group (NS group, n=8) was defined as control. After high-fat diet, the rats with resistin levels higher than X^-±2s of resistin were defined as diet-induced hyper-resistinemia model group (HRE group, n=8) and those with resistin levels lower than X^-±s of resistin were defined as diet-induced normal resistin model group (NRE group, n=8); the normal control group (NC group, n=8) received standard feed at the same time. Concentrations of FFA with different resistin levels were detected. Results The levels of the serum FFA and insulin in RE group was higher than those in NS group (P<0.01). The level of FFA increased in HRE group than that in NRE group and NC group (P<0.01). Resistin levels were obviously correlated with serum FFA, insulin, glucose, insulin sensitivity index (ISI), weight and Lee index (P<0.01). Even after correction for insulin, glucose, ISI, weight and Lee index, the resistin level was still correlated significantly with FFA (r=0.615, P<0.01). Conclusion Both extrinsic and intrinsic hyper-resistin can induce higher FFA levels in rats. The hyper-resistin in rats may play an important role in lipid metabolism disorder.

Key words: Rat, Resistin, Free fatty acid, Obesity