Abstract: This experiment was designed to study the effects and possible mechanism of Laminaria japonica polysaccharide (LJPS) on leptin level in serum and leptin receptor expression in hypothalamus of hyperlipemia mice.80 male mice were randomly divided into control group,model group,and LJPS treatment groups.The hyperlipemia model of mice were established by feeding fat-rich forage for 4 weeks and treated by LJPS orally.Lipids levels in serum were determined by automatic biochemical analyzer and leptin levels in serum were determined by enzyme linked immunosorbent assay (ELISA).The immunohistochemistry and western blot were used to detect the expressions of leptin receptors (OBR) proteins and RT-PCR was used to detect the expression of OBR mRNA in hypothalamus tissue.After treated with LJPS,the serum levels of lipids and leptin decreased significantly compared with those in model group (P<0.05).In hypothalamus tissue,the expression levels of OBR mRNA and its protein were significantly higher than those in model group (P<0.05).Hence,it was concluded that LJPS might reduce blood lipid level in hyperlipemia mice by promoting the expressions of OBR and reducing leptin resistance.

Key words: Laminaria japonica polysaccharide, hyperlipemia, leptin, leptin receptor, leptin resistance, mice