The protein expression and localization of leptin and its long form receptor(OB-Rb) were detected by western blottig methord and a confocal laser scanning microscope.The results showed that leptin protein level was higher in virgin,the lowest in lactation.Then OB-Rb was higher in virgin and pregnancy,lower in lactation,and recovered to the original level in involution.

Bovine whey contains many kinds of high-abundance proteins and varied interferential impurity,so it’s hard to obtain satisfied protein images of bovine whey in two dimensional electrophoresis(2-DE).Protein extraction from bovine whey is a key step to achieve high-resolution protein separation in 2-DE.Four routine total protein extraction methods were compared in order to determine an optimal one in 2-DE analysis for bovine whey.Bovine whey protein were extracted by direct schizolysis,TCA-acetone,trizol precipitation and 2-D clean up kit.The concentration of total protein was measured by 2-D quant kit,bovine whey protein were separated using SDS-PAGE and 2-DE.The data showed that use of 2-D clean up kit gave maximum protein yield,and the use of trizol gave the lowest.The result of SDS-