"Neuroendocrine disruption caused by the indoor organohalogen - - PowerPoint PPT Presentation

Martha León Olea Ph. D.

• Depto. Neuromorfología Funcional

Dirección de Investigaciones en Neurociencias

Instituto Nacional de Psiquiatría “Ramón de la Fuente Muñiz” México D.F.

"Neuroendocrine disruption caused by the indoor organohalogen pollutants PBDEs”

TOXIC EARTH:TOXIC BODIES Binational Perspectives in Environmental Health

If you've been in contact with You can be contaminated

PBDEs Blood concentrations in Mexican children

Chemosphere Maldonado et al., 2009

PCBs Blood concentration in Mexican children

San Nicolas, Tequisquiapan, Qro. Trejo-Acevedo A. Chemosphere. 2009

During physiological challenges:

PACAP:

somatodendritic AVP release PACAP and PAC-1 receptor This suggests that PACAP may function as a physiological brake for excessive release of VP during intense or prolonged physiological

• demand. Without this physiological brake, pituitary VP stores are depleted

and plasma osmolality is dysregulated. Gillard et al., 2006.

NO-

Nitric oxide is critical for AVP hormone release regulation. During hyperosmotic stimulation: AVP release (somatodendritic) and plasmatic AVP

PCBs and PBDEs

X Nitric Oxide Synthase

This suggest that exposure to PCB-like compounds may lead to dysregulation of body water.

Kadekaro, 2004; Kadowaki, et al., 1994; Villar et al., 1994; Ueta et al., 1998; Sharma and Kodavanti, 2002; Coburn et al., 2006, 2007; Gillard et al, 2007.

Aim: To examine the effect of PCB (Aroclor-1254) and PBDE (DE-71) perinatal exposure on the immunoreactivity to VP, PACAP and NOS, in SON and PVN magnocellular neurons of adult rats, both hydrated and dehydrated.

Perinatal exposure to Aroclor 1254 or DE-71

Oral doses Aroclor 1254: GD 10-19: 30 mg/kg/d DE-71: GD 6- PND 21: 3 months

Plasma

• smolality
• Histological processing of the brain
• NADPH-d histochemistry to NOS,
• Immunohistochemistry

to VP, PACAP and nNOS,

Sacrifice

Hydrated Control Treated : A-1254 DE-71

Drinking water

Dehydrated NaCl Treated: NaCl + A-1254 NaCl + DE-71

Drinking 2% NaCl sol.

Pn day 10 Experimental Groups 5 days

Control Aroclor-1254

10 Pn days

Nitric Oxide Synthase Activity (NADPH-d), 10 Pn day

PVN SON PeF

Integrated Optical Density

NADPH-d: 3 Months

Control Aroclor-1254 NaCl + Aroclor-1254 NaCl

AVP/nNOS Immunoreactivity FITC/TRITC

(green/red)

PVN

Control NaCl Aroclor-1254 NaCl + Aroclor-1254

IOD

Aroclor 1254

Control DE-71 Control DE-71

NaCl NaCl + DE-71 NaCl NaCl + DE_71

nNOS Immunoreactivity, DE-71

Densidad Optica Integrada

nNOS en PVN + DE-71

Densidad Optica Integrada

nNOS en SON + DE-71

Integrated optical density

TRITC

1000 2000 3000 4000

Control DE-71 NaCl NaCl+DE-71

n = 4 ns= 14 n = 4 ns= 14 n = 5 ns= 15 n = 4 ns= 13

Integrated Optical Density

** *** *

Vasopressin in PVN / DE-71 Male

1000 2000 3000 4000

Control DE-71 NaCl NaCl+DE-71

n = 4 ns= 11 n = 4 ns= 13 n = 5 ns= 12 n = 4 ns= 13

Integrated Optical Density Vasopressin in SON / DE-71 Male

* *** *** *

AVP Immunoreactivity, DE-71

Control DE-71 Control DE-71

NaCl NaCl + DE_71 NaCl NaCl + DE_71

PACAP Immunoreactivity DE-71 PVN

Control DE-71 Control DE-71

SON

NaCl NaCl+DE-71 NaCl NaCl+DE-71 Integrated Optical Density

Conclusions:

• Perinatal exposure to PCBs and PBDEs produces long term alterations

in the immunoreactivity to AVP, PACAP and nNOS in the adult SON and PVN.

• The neurotoxic effects of PCBs are similar to those observed for

PBDEs.

• In 10 Pn day PCB-exposed pups there is a decrease in the number of

nitrergic neurons and signs of morphological damage and neuronal death.

• The

dehydration-induced increase

• f

VP, PACAP and nNOS immunoreactivity is absent in treated rats.

• Pups exposed to PCBs and PBDEs are prone to subtle but measurable

developmental problems.

PCBs and PBDEs alter AVP content and the regulatory factors PACAP and NO, leading to dysregulated hydroelectrolitic balance which is essential for normal physiology.

Carolina Miller Pérez Ph. D. Eduardo Sánchez Islas Ph. D. Samuel Mucio Ramírez. Biol. José Mendoza Sotelo EMEACM. René Garduño Gutiérrez. Postgraduate candidate Feliciano Camacho García Technician

Departamento de Neuromorfología Funcional

This work was supported by grants: UC-MEXUS-CONACYT; Fondo para la investigación Miguel Alemán; Fondo para la investigación Instituto Nacional de Psiquiatria R.F.M. The experiments was conducted in accordance with national and institutional guidelines for the protection of animal subjects.

"What if BEFORE we start doing What we have to do, we BEGIN by doing what we should HAVE DONE ?"

PACAP Immunoreactivity

Control Aroclor-1254 Control Aroclor-1254 NaCl NaCl+Aroclor-1254 NaCl NaCl+Aroclor-1254

PVN SON

PACAP in PVN / Aroclor-1254

500 1000 1500 2000

Control A1254 NaCl NaCl+A1254 Integrated Optical Density

*** *** ***

A

Aroclor 1254

PACAP Immunoreactivity DE-71 PVN

Control DE-71 Control DE-71

SON

NaCl NaCl+DE-71 NaCl NaCl+DE-71 Integrated Optical Density

We also performed polymerase chain reaction (PCR) preliminary studies in PVN and SON micropunches to understand the disrupting effects of the PACAP gene expression in response to the exposition of PCBs.

The flame retardant industry argues that the benefit accrued through saving lives by fire prevention outweighs the cost incurred by any medical

• consequences. Over time however, this cost/benefit radio is likely to shift.

In the meantime, it is imperative that a more aggressive approach be taken to circumvent or regulate their use.

Some reported PCBs and PBDEs effects

• They cross the placental barrier.
• They are found in blood and breast milk.
• Neurotoxicity (dopamine, nitric oxide, PKC, NOS, Ca +).
• Endocrine system: Thyroid, estrogenicity, vasopressin.
• Immune system depression.
• Carcinogenic in animals and humans.
• Children are the most affected: - impaired growth and development
• motor behavior
• learning and memory

Safe S., 1993; Jacobson and Jacobson, 1996; Tilson and Kodavanti, 1997; Sharma and Kodavanti, 2002; Kodavanti and Curras-Collazo, 2010.

Diphenyl ether mixture used in the manufacture of textiles and polyurethane

• foams. DE-71 is composed of the congeners 2,2´,4,4´,5-pentabromodiphenyl ether

(PBDE 99; pentaBDE) and 2,2´,4,4´-tetrabromodiphenyl ether (PBDE 47; tetraBDE) as the major constituents (Hale et al., 2001; LaA Guardia et al., 2006). A number of studies suggest that DE-71 has the potential to disrupt endocrine homeostasis and reproductive development (Stoker et al., 2004, 2005) and this mixture has been shown to significantly decrease circulating total serum thyroxin (T4) in perinatally exposed rats (Ellis-Hutchings et al., 2006).

DE-71

Generalized structure of PCBs Generalized structure of PBDEs

Hay 187 químicos considerados como tóxicos para los

• rganismos vivos.

(Comité Intergubernamental de Negociación sobre “Contaminantes Orgánicos Persistentes”, (COP).

Dentro de los 12 más tóxicos, están los plaguicidas como el DDT y Los Bifenilos policlorinados (PCB).

Kunisue et al., 2003 Trejo-Acevedo et al., 2009

Prueba de condicionamiento de evitación inhibitoria

AVP/nNOS Immunoreactivity FITC/TRITC

SON

Control NaCl Aroclor-1254 NaCl + Aroclor-1254

IOD

Aroclor 1254