The effects of polybrominated diphenyl ethers (PBDEs) on adipocyte functionality in vitro and in vivo

Abstract

PBDEs are flame retardants found in furniture, carpets and electronics. These organic pollutants are highly lipophilic and accumulate in the adipose tissue of animals and humans. However, the effects of PBDEs on adipocyte metabolism are unknown. The purpose of this study was to determine the effects of penta-PBDE on lipolysis and glucose oxidation in rat adipocytes in vitro and in vivo. In vitro, adipocytes from 12 male Sprague-Dawley rats were isolated and incubated for 90 minutes with either 0, 15 or 30ug/ml PBDEs (4 rats/group.) In vivo, male Sprague-Dawley rats weighing 120g were gavaged daily for 4 weeks with either 18mg/kg PBDEs or corn oil (12 rats/group). Adipocytes from in vivo and in vitro treatments were tested for lipolytic response to epinephrine and [U-14C] glucose oxidation response to insulin. Rat weight gain was similar in all groups throughout the study. In vitro data show that incubation with PBDEs for 90 minutes had no effect on lipolysis or glucose oxidation in rat adipocytes. In vivo data show that after 4 weeks, basal lipolysis was increased by 58% and maximal lipolysis was increased by 22%, compared to control. There was a 41% decrease in maximal glucose oxidation in rats treated with PBDEs for 4 weeks, compared to controls. In summary, although incubation of adipocytes with PBDEs does not change adipocyte functionality, a low daily dose of PBDEs to rats increased basal and maximal lipolysis and decreased maximal glucose oxidation in freshly isolated rat adipocytes. Whether these changes persist and contribute to permanently altered adipocyte function remains to be determined. Supported by Agr. Exp. Stn. Grant NH00432.