BackgroundBisphenol A (BPA) is a widespread endocrine-disrupting chemical used as the base compound in the manufacture of polycarbonate plastics. In humans, epidemiological evidence has associated BPA exposure in adults with higher risk of type 2 diabetes and heart disease.ObjectiveWe examined the action of environmentally relevant doses of BPA on glucose metabolism in mice during pregnancy and the impact of BPA exposure on these females later in life. We also investigated the consequences of in utero exposure to BPA on metabolic parameters and pancreatic function in offspring.MethodsPregnant mice were treated with either vehicle or BPA (10 or 100 μg/kg/day) during days 9–16 of gestation. Glucose metabolism experiments were performed on pregnant mice and their offspring.ResultsBPA exposure aggravated the insulin resistance produced during pregnancy and was associated with decreased glucose tolerance and increased plasma insulin, triglyceride, and leptin concentrations relative to controls. Insulin-stimulated Akt phosphorylation was reduced in skeletal muscle and liver of BPA-treated pregnant mice relative to controls. BPA exposure during gestation had long-term consequences for mothers: 4 months postpartum, treated females weighed more than untreated females and had higher plasma insulin, leptin, triglyceride, and glycerol levels and greater insulin resistance. At 6 months of age, male offspring exposed in utero had reduced glucose tolerance, increased insulin resistance, and altered blood parameters compared with offspring of untreated mothers. The islets of Langerhans from male offspring presented altered Ca2+ signaling and insulin secretion. BrdU (bromodeoxyuridine) incorporation into insulin-producing cells was reduced in the male progeny, yet β-cell mass was unchanged.ConclusionsOur findings suggest that BPA may contribute to metabolic disorders relevant to glucose homeostasis and that BPA may be a risk factor for diabetes.

. The pancreatic β-cell as a target of estrogens and xenoestrogens: Implications for blood glucose homeostasis and diabetes. Molecular and Cellular Endocrinology, Elsevier, 2009, 304 (1-2) Please cite this article as: Nadal, A., Alonso-Magdalena, P., Soriano, S., Quesada, I., Ropero, A.B., The pancreatic ␤-cell as a target of estrogens and xenoestrogens: Implications for blood glucose homeostasis and diabetes, Molecular and Cellular Endocrinology (2008), doi:10.1016/j.mce.2009 This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. THE PANCREATIC -CELL AS A TARGET OF ESTROGENS AND XENOESTROGENS: IMPLICATIONS FOR BLOOD GLUCOSE HOMEOSTASIS AND DIABETESAngel Rosen & Spiegelman, 2006;Fritsche et al., 2008). During the fasting state, insulin remains at low levels because plasma glucose concentration is low. In this situation, the levels of the counter-regulatory hormones, glucagon, adrenaline and corticosteroids are increased to promote hepatic glucose production. In contrast, insulin, the only hormone in the body able to decrease blood glucose levels, is increased during the fed state. Insulin decreases blood glucose by promoting adipocyte and muscle glucose uptake, as well as by preventing the liver from producing glucose by suppressing glycogenolysis and gluconeogenesis (Fritsche et al., 2008). neurotransmitters, hormones and nutrients, among which glucose is the most important.Normally, in response to short glucose stimulation, insulin biosynthesis is regulated by the increased translation of the preproinsulin transcript. After a prolonged glucose exposure, however, it is regulated via the insulin gene transcription (Orland et al., 1985;Permutt & Rotwein, 1983;Poitout et al., 2006). Both transcriptional and translational regulation of insulin biosynthesis is essential to maintain the intracellular stores of insulin on a long term basis.The secretory response of -cells depends on their electrical activity. This consists of oscillations of the membrane potential that range from electrically silent periods to depolarised plateaus on which Ca 2+ -action potentials originate (Rorsman et al., 2000).The classical stimulus-secretion coupling that drives insulin release involves the closure of K ATP channels by increasing the intracellular ATP/ADP ratio (Ashcroft et al., 1984) and diadenosine polyphosphates concentration (DPs) (Ripoll et al., 1996) oscillatory pattern is originated (Nadal et al., 1999;Santos et al., 1991;Valdeolmillos et al., 1989), which triggers a pulsatile insulin secretion (Barbosa et al., 1998;Gilon et al., 1993;Dyachok et al., 2008). Estrogens, estrogen receptors and blood glucose homeostasisT...

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