PO514. FISH OIL MODULATES IMMUNE CELL INFILTRATION IN ADIPOSE TISSUE, BUT NOT REVERSE INSULIN RESISTANCE IN OBESE MICE

Hypercaloric diets are associated with metabolic and inflammatory disturbances in adipose tissue leading to insulin resistance. Studies have demonstrated that high fat diet causes immune cells infiltration with lymphocytes preceding macrophage accumulation. Fish oil is characterized by anti-inflammatory effects. Effect of fish oil on insulin resistance prevention is well characterized, but reversion effects are discrepant. Animals were fed with regular chow or high fat diet for 8 weeks. Fish oil supplementation occurred for 4 weeks. High-fat diet induced glucose intolerance and hyperinsulinemia, demonstrating insulin resistance, but fish oil did not ameliorate glucose homeostasia and hepatic content of tryacilglycerol, cholesterol and glycogen. In epidydimal adipose tissue, fish oil was able to reduce M1 macrophages infiltration, characterized by the production of proinflammatory cytokines, such as TNF- alpha, and increase CD4 T cell, in a regular chow. However, in animals fed with high fat diet fish oil increased M1 infiltration. Is interesting to study how each type of lymphocyte affect immune cell infiltration in adipose tissue. We concluded that fish oil supplemented for 4 weeks in animals receiving high-fat diet was not able to reverse preexisting insulin resistance. However, fish oil was able to affect immune cell infiltration in epididymal AT. Fish oil is able to modulate obesity-associated inflammation of the different ways depending on the diet used. Based on our results, we strong suggest the importance of evaluating each type of T lymphocyte is modulated in each specific adipose tissue.