Abstract: 【Objective】An experiment was conducted to investigate the effect of lipopolysaccharide (LPS) challenge on peroxisome proliferator-activated receptor γ (PPARγ) protein expression in immune organs and immune cells of weaned pigs. 【Method】Pigs were allotted to two treatments (6 replicates/treatment and 1 pig/replicate). The pigs in the treatment group were injected intraperitoneally with 100μg/kg BW LPS, whereas pigs in the control group were injected with an equivalent amount of sterile saline. Blood samples were collected at 3h post-challenge for isolating plasma or leucocytes. Following blood collection, the pigs were slaughtered to collect spleens, thymus and intestinal lymph nodes. PPARγ protein expression of immune organs and the leucocytes were determined by Western Blot. 【Result】(1) LPS challenge increased significantly plasma interleukin-6, tumor necrosis factor-α, cortisol and Prostaglandin E2 (P<0.05), and decreased insulin and insulin-like growth factor-1 (P<0.05); (2) LPS challenge decreased significantly plasma glucose, total protein, albumin and globulin (P<0.05); (3) LPS challenge increased significantly PPARγ protein expression of spleens (P<0.05), thymus (P<0.1) and leucocytes (P<0.05), and decreased PPARγ protein expression of intestinal lymph nodes (P<0.05).【Conclusion】Immunological stress changes PPARγ protein expression in immune organs and immune cells of weaned pigs, which indicates PPARγ plays an important role in regulation of immunological stress, and may prove to be an important target of alleviating the immunological stress in pigs.

Key words: Weaned pigs, LPS, PPARγ