The Feline Thyroid Gland: The Feline Thyroid Gland: A Model for Endocrine A Model for Endocrine Disruption by Disruption by Polybrominated Diphenyl Polybrominated Diphenyl Ethers? Ethers? Donna Mensching, DVM, MS, DABVT, Donna Mensching, DVM, MS, DABVT, DABT DABT September 29, 2010 September 29, 2010
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The Feline Thyroid Gland: A Model for Endocrine Disruption by Polybrominated Diphenyl Ethers?
The Feline Thyroid Gland: A Model for Endocrine Disruption by Polybrominated Diphenyl Ethers?. Donna Mensching, DVM, MS, DABVT, DABT September 29, 2010. Feline Hyperthyroidism. Autonomously functional thyroid adenoma(s). Analogous to toxic multinodular goiter (TNG). - PowerPoint PPT Presentation
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The Feline Thyroid Gland:The Feline Thyroid Gland:A Model for Endocrine Disruption byA Model for Endocrine Disruption by
Endocrine Disruptive Properties of PBDEsEndocrine Disruptive Properties of PBDEs
Thyroid HormoneThyroid Hormone
vsvs
BrBr
Br Br
BrBr
BrBrBrBr
Hydroxylated Hydroxylated Metabolites of PBDESMetabolites of PBDES
Endocrine Disruptive Properties of PBDEsEndocrine Disruptive Properties of PBDEs
Meerts et al., 2000Meerts et al., 2000
Induction Induction ofof
phase Iphase Iandand
phase IIphase IIenzymesenzymes(UDPGT)(UDPGT)
Norris et al., 1975Norris et al., 1975
Stoker et al., 2004Stoker et al., 2004
Kuriyama et al. 2007Kuriyama et al. 2007
Marsh et al. 1998Marsh et al. 1998
Research ObjectivesResearch Objectives
Compare PBDE burdens in serum & adipose tissue in age-matched Compare PBDE burdens in serum & adipose tissue in age-matched euthyroid vs hyperthyroid cats to determine if hyperthyroidism euthyroid vs hyperthyroid cats to determine if hyperthyroidism
correlates with higher residuescorrelates with higher residues
Evaluate the PBDE content of commercial canned cat foods & Evaluate the PBDE content of commercial canned cat foods & household dust to identify predominant exposure sources household dust to identify predominant exposure sources
for domestic catsfor domestic cats
Materials and MethodsMaterials and Methods
Silica Gel ChromatographySilica Gel Chromatography
GC/HRMS Analysis of Sample Extracts for PBDEs: GC/HRMS Analysis of Sample Extracts for PBDEs: Congeners 17, Congeners 17, 2828, , 4747, 49, 66, 71, 85, , 49, 66, 71, 85, 9999, , 100100, 138, , 138, 153153, , 154154, , 183183, 190, and , 190, and 209209
Comparison of Log PBDEs (lipid weight) in Serum of Comparison of Log PBDEs (lipid weight) in Serum of Client-Owned Euthyroid (a) and Hyperthyroid (b) Cats vs AgeClient-Owned Euthyroid (a) and Hyperthyroid (b) Cats vs Age
Research ObjectivesResearch Objectives
Compare PBDE burdens in serum & adipose tissue in age-matched Compare PBDE burdens in serum & adipose tissue in age-matched euthyroid vs hyperthyroid cats to determine if hyperthyroidism euthyroid vs hyperthyroid cats to determine if hyperthyroidism
correlates with higher residuescorrelates with higher residues
Evaluate the PBDE content of commercial canned cat foods & Evaluate the PBDE content of commercial canned cat foods & household dust to identify predominant exposure sources household dust to identify predominant exposure sources
for domestic catsfor domestic cats
PBDEs in Commercial Canned Cat FoodsPBDEs in Commercial Canned Cat Foods
Calculated Daily Intake of PBDEs in CatsCalculated Daily Intake of PBDEs in Cats
At the high end,At the high end, this represents 1.3% of the this represents 1.3% of the lowestlowest singlesingle acutelyacutely toxictoxic
PBDE dose known to disrupt thyroid function PBDE dose known to disrupt thyroid function in laboratory animals.in laboratory animals.
Domestic cats are highly exposed to PBDEs Domestic cats are highly exposed to PBDEs with the highest recorded levels on the planet:with the highest recorded levels on the planet:51,063 vs previous high of 39,000 ng/g lipid51,063 vs previous high of 39,000 ng/g lipid
ConclusionsConclusions
Domestic cats are highly exposed to PBDEs Domestic cats are highly exposed to PBDEs with the highest recorded levels on the planetwith the highest recorded levels on the planet::51,063 vs previous high of 39,000 ng/g lipid51,063 vs previous high of 39,000 ng/g lipid
Total PBDE serum burdens do not significantly Total PBDE serum burdens do not significantly differ between client-owned differ between client-owned
euthyroid and hyperthyroid cats. euthyroid and hyperthyroid cats.
ConclusionsConclusions
Feral cats have significantly lower PBDE burdens Feral cats have significantly lower PBDE burdens in serum than both euthyroid and in serum than both euthyroid and
Feral cats have significantly lower PBDE burdens Feral cats have significantly lower PBDE burdens in serum than both euthyroid and in serum than both euthyroid and
Dust is likely the primary route of Dust is likely the primary route of exposure of domestic cats to PBDEs.exposure of domestic cats to PBDEs.
ConclusionsConclusions
Feral cats have significantly lower PBDE burdens Feral cats have significantly lower PBDE burdens in serum than both euthyroid and in serum than both euthyroid and
Dust is likely the primary route of Dust is likely the primary route of exposure of domestic cats to PBDEs.exposure of domestic cats to PBDEs.
Total PBDEs were significantly higher in dust from Total PBDEs were significantly higher in dust from homes of hyperthyroid cats versus homes of euthyroid cats.homes of hyperthyroid cats versus homes of euthyroid cats.
ConclusionsConclusions
The Feline Thyroid Gland:The Feline Thyroid Gland:A Model for Endocrine Disruption byA Model for Endocrine Disruption by