Effects of Perinatal Polychlorinated Biphenyl Mixtures on Estrogen Receptor Beta, Hippocampus, and Learning and Memory
Year: 2007
Type: article
Abstract: Polychlorinated biphenyls (PCBs) are a group of 209 structurally related chemical compounds (congeners) that were once used in industrial applications.PCBs have been reported to cause a variety of health effects including endocrine disruption, immunologic, reproductive, and neurologic, behavioral deficits.They are not only a potential health threat to adult humans, but also to the developing fetus and infant because of perinatal exposure through placenta during pregnancy and through milk during lactation.In the present study, a mixture of two PCB congeners, non-coplanar (PCB 47) and coplanar (PCB 77), were administered to young female Sprague-Dawley rats by route of maternal dietary consumption (either 12.5 ppm or 25.0 ppm, w/w).Alterations in learning and memory were examined by radial arm maze on PND 27.After behavior tests were completed, the rats were transcardially perfused, and brains were excised.Immunohistochemistry for ER-β was carried out on free-floating sections.Sections were stained with cresyl violet stain, and hippocampal area was measured.A qualitative comparison suggested a greater intensity of ER-β staining in female rat hippocampus exposed to PCB 47/77 at 25 ppm concentration.A decrease in the hippocampal area measurement was observed in the case of PCB 25 exposed rats.Significant behavioral effects involving spatial learning and memory were not observed.However, animals exposed to PCB 47/77 at 25 ppm showed a trend toward improved performance.Taken together, these data support that low doses of PCB mixtures act as an endocrine disruptor, with subsequent effects on brain morphology and behavior.iii DEDICATION To my parents, who always believed in me vi 3.5.Summary of Results 24 4. DISCUSSION 4.1.Complex Endocrine Systems and Limitations of Such Studies 26 4.2.Influence of PCBs on Memory 26 4.3.PCB and Hippocampus Size 30 4.4.Apoptosis 31 4.5.PCB and Estrogen Receptor-Beta 32 4.6.Is It only Estrogen?34 4.7.Maternal Behavior on PCB exposure 34 5.
Author: Avanti Desai
Institution: Bowling Green State University
Language: English
Subfield: Health, Toxicology and Mutagenesis
Field: Environmental Science
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W2240900579