You are here:
Neuroendocrine Actions of Organohalogens: Thyroid Hormones, Arginine Vasopressin, and Neuroplasticity
Citation:
KODAVANTI, PRASADA RAO S. AND M. C. Curras-Collazo. Neuroendocrine Actions of Organohalogens: Thyroid Hormones, Arginine Vasopressin, and Neuroplasticity. Frontiers in Neuroendocrinology. ELSEVIER, AMSTERDAM, Holland, 31(4):479-496, (2010).
Impact/Purpose:
This review article highlights the role of neuroendocrine hormones, organohalogen effects. and neuroplasticity. Organohalogen compounds are global environmental pollutants that are highly persistent, bioaccumulative, and cause adverse effects in humans and wildlife. Although several organohalogens are banned or voluntarily withdrawn from usage by the manufacturer, new organohalogens such as perfluorinated compounds and brominated flame retardant alternatives like Decabromoethane continue to be used in society, Given the widespread use of these new organohalogens in household items and consumer products, indoor contamination may be a significant source of human exposure. Persistent health effects produced by these organohalogens may continue for a long time, even after a widespread ban is imposed on their production. One significant concern with regard to health effects associated with exposure to organochlorines is endocrine disruption, which includes effects on male and female reproduction, breast development and cancer, neuroendocrine and thyroid systems. With regard to neuroendocrine effects of organohalogens, evidence is accumulating that the vasopressin system is also targeted; AVP regulation and related functions such as osmoregulation, blood pressure, sexual function and social behavior show signs of disruption. In the case of the thyroid system the timing of exposure seems to playa major role in the outcome of adverse effects. For example, there is a rapid brain growth spurt during postnatal period in rat. Since TH play an important role in the growth ofthe nervous system, slight perturbations in TH homeostasis at postnatal period can have adverse effects in adulthood. Also, the physiological processes controlled by neuroendocrine systems are highly complex with interdependent levels of organization. Therefore, a clear understanding of the role of the neuroendocrine system in mediating the adverse effects caused by organohalogens is challenging. Current literature provides conflicting evidence regarding the role of organohalogen-induced neuroendocrine disruption in the neuroplasticity that includes both learning and brain structure. Additional studies are needed to establish the role of endocrine disruption in the nervous system function and development
Description:
Organohalogen compounds are global environmental pollutants. They are highly persistent, bioaccumulative, and cause adverse effects in humans and wildlife. Because of the widespread use of these organohalogens in household items and consumer products, indoor contamination may be a significant source of human exposure; especially for children. One significant concern with regard to health effects associated with exposure to organohalogens is endocrine disruption. This review focuses on PCBs and PBDEs as old and new organohalogens and discuss their effects on two neuroendocrine systems; thyroid hormones and arginine vasopressin system (AVP). Regarding neuroendocrine effects of organohalogens, there is considerable information on thyroid system as a target and evidence is now accumulating that the AVP system is also a target. In the case of the thyroid system, the timing of exposure seems to play a major role in the outcome of adverse effects. Also, the physiological processes controlled by neuroendocrine systems are highly complex with interdependent levels of organization. Therefore, a clear understanding of the role of the neuroendocrine system in mediating the adverse effects caused by organohalogens is challenging. Current literature provides conflicting evidence regarding the role of organohalogen-induced neuroendocrine disruption in the neuroplasticity that includes both learning and brain structure. Additional studies are needed to establish the role ofendocrine disruption in the nervous system function and development.
