However, plasma resistin concentration has never been determined during lactation in the dairy cow and the role of resistin in bovine adipose tissue has never been studied. We investigated the profile of plasma resistin, insulin, glucose and non esterified fatty acid concentrations around the time of parturition and at the start of the first lactation in dairy cows. For the second lactation in the same animals, we then investigated mRNA and protein levels for resistin and the phosphorylation rates of several insulin receptor signaling components in vivo in subcutaneous adipose tissue in early lactation and mid-gestation. Finally, for the fifth lactation in the same animals, we analyzed the effects of bovine recombinant resistin on lipolysis in vitro in adipose tissue explants performed between one and two months after calving. The hyperphagia required to meet those demands develops slowly, consequently mobilization of SNS-314 Mesylate endogenous reserves is observed. These metabolic adaptations are coordinated by changes in the plasma concentration of key hormones. For example, the secretion of growth hormone is elevated in early lactation and promotes the mobilization of nonesterified fatty acids from adipose tissue and their oxidative use by the rest of the body. Cathecolamineinduced lipolysis in adipose tissue depots is also considered to be the key metabolic pathway for providing endogenous energy in times of high energy demand in the peripartal dairy cow. Recently it has been shown that NEFAs activate the AMPKa signaling pathway to increase lipid oxidation and decrease lipid synthesis in bovine hepatocytes, which in turn, could generates more ATP to relieve the negative energy balance in transition dairy cows. AMPK activation is regulated by various adipokines including adiponectin in bovine hepatocytes and resistin in bovine granulosa cells. Consequently it plays a key role in the control of body fat mass. Here, we show for the first time that plasma resistin concentrations increase one week after calving in a similar manner to NEFA levels in dairy cows. We also found that resistin mRNA and protein levels in adipose tissue were higher one week post partum than at five months of gestation. Conversely, the level of phosphorylation of several components of the insulin receptor signaling pathway in adipose tissue was Tenalisib significantly lower one week after calving than at 5 MG. We also showed that resistin was produced in bovine mature adipocytes and that recombinant bovine resistin increased the release of glycerol and levels of mRNA for ATGL and HSL in adipose tissue explants. Our data suggest that the high levels of resistin in the plasma and adipose tissue observed immediately after calving may contribute to lipid mobilization during early lactation in dairy cows. Resistin is considered to be a potential factor underlying obesity-mediated insulin resistance and type 2 diabetes. In humans and rodents, serum resistin levels are about 2 to 15 ng/ml, but considerable variability has been noted between species and types of assay. In this study, we obtained values for plasma resistin concentration of 30 to 90 ng/ml in dairy cows.