Andrea A Hoppe1, Gale B Carey. 1. Department of Animal and Nutritional Sciences, University of New Hampshire, Kendall Hall, 129 Main St., Durham, NH 03824, USA.
Abstract
OBJECTIVE: Obesity is thought to result from poor diet and insufficient exercise. An additional factor may be endocrine-disrupting environmental chemicals that contaminate the air, water, and food supply. We tested the hypothesis that a class of lipid-soluble flame retardant chemicals known to accumulate in adipose tissue, polybrominated diphenyl ethers (PBDEs), disrupts insulin and isoproterenol sensitivity of isolated rat adipocytes. RESEARCH METHODS AND PROCEDURES: Six-week-old Sprague-Dawley rats were gavaged daily with 14 mg/kg body weight (BW) pentabrominated diphenyl ether (penta-BDE) in corn oil (n = 24) or corn oil alone (n = 24). At 2 and 4 weeks of treatment, epididymal fat pad adipocytes were isolated, and isoproterenol-stimulated lipolysis, insulin-stimulated glucose oxidation, and adipocyte size were measured. RESULTS: There was no alteration in adipocyte metabolism after 2 weeks of in vivo penta-BDE treatment, but after 4 weeks of treatment, adipocytes averaged a 30% increase in isoproterenol-stimulated lipolysis and a 59% decrease in insulin-stimulated glucose oxidation, compared with control. There were no differences in average rat BW and adipocyte size between treated and control rats, but plasma total thyroxine level in 2- and 4-week treated rats was 30% of control. DISCUSSION: Daily exposure of rats to 14 mg/kg BW penta-BDE for 4 weeks has no effect on animal or adipocyte size but significantly alters insulin and isoproterenol-stimulated metabolism of isolated adipocytes. These alterations, hallmark features of metabolic obesity, suggest the need for further research on the contribution of lipid-soluble, endocrine-disrupting environmental chemicals to the obesity epidemic.
OBJECTIVE: Obesity is thought to result from poor diet and insufficient exercise. An additional factor may be endocrine-disrupting environmental chemicals that contaminate the air, water, and food supply. We tested the hypothesis that a class of lipid-soluble flame retardant chemicals known to accumulate in adipose tissue, polybrominated diphenyl ethers (PBDEs), disrupts insulin and isoproterenol sensitivity of isolated rat adipocytes. RESEARCH METHODS AND PROCEDURES: Six-week-old Sprague-Dawley rats were gavaged daily with 14 mg/kg body weight (BW) pentabrominated diphenyl ether (penta-BDE) in corn oil (n = 24) or corn oil alone (n = 24). At 2 and 4 weeks of treatment, epididymal fat pad adipocytes were isolated, and isoproterenol-stimulated lipolysis, insulin-stimulated glucose oxidation, and adipocyte size were measured. RESULTS: There was no alteration in adipocyte metabolism after 2 weeks of in vivo penta-BDE treatment, but after 4 weeks of treatment, adipocytes averaged a 30% increase in isoproterenol-stimulated lipolysis and a 59% decrease in insulin-stimulated glucose oxidation, compared with control. There were no differences in average rat BW and adipocyte size between treated and control rats, but plasma total thyroxine level in 2- and 4-week treated rats was 30% of control. DISCUSSION: Daily exposure of rats to 14 mg/kg BW penta-BDE for 4 weeks has no effect on animal or adipocyte size but significantly alters insulin and isoproterenol-stimulated metabolism of isolated adipocytes. These alterations, hallmark features of metabolic obesity, suggest the need for further research on the contribution of lipid-soluble, endocrine-disrupting environmental chemicals to the obesity epidemic.
Authors: Mary Turyk; Giamila Fantuzzi; Victoria Persky; Sally Freels; Anissa Lambertino; Maria Pini; Davina H Rhodes; Henry A Anderson Journal: Environ Res Date: 2015-04-22 Impact factor: 6.498
Authors: Michele La Merrill; Bittu S Kuruvilla; Daniel Pomp; Linda S Birnbaum; David W Threadgill Journal: Environ Health Perspect Date: 2009-05-18 Impact factor: 9.031