What are we learning from wildlife about endocrine disruption that is relevant to human health? Dr. Peter L. deFur Center for Environmental Studies Virginia Commonwealth Univ June
In A Word Everything Well… Almost everything Considering all “not people” animals
Pesticide companies have disrupted insect hormone systems for ca. 40 years All good science is a story – of inquiry and discovery Hormonal control of metamorphosis in insects is affected by molting (ecdysone) and juvenile hormones
Insect Juvenile Hormone Tebufenozide Ecdysone
Two clutches of eggs in one nest Cross-billed cormorant In The Story continues- pick up to the early 1990’s Beginning with wildlife in recent years
Mimic normal action Abnormal actionBlocked action hormone EDC R RR R= hormone receptor; EDC = endocrine disrupting chemical Model of how EDC acts on hormone-receptor interactions
What can go wrong or awry with chemicals in the environment?
Fish sex change First reported in Florida in 1970’s Male Goby fish showed female characteristics Downstream from pulp mill effluent Sitosterol was active chemical from trees Reported in other rivers with pulp effluent Resurfaced in England in thanks to John Sumpter
“steroid” mechanism of action Second messenger mechanism How does a system work?
Lessons thus far Can synthesize hormones and mimics Untimely exposures can harm Endogenous hormones when exogenous— Mechanisms and processes Low levels can harm
Ecy receptor RxR receptor
17B-Estradiol20- hydroxyecdysone Diethylstilbestrol (DES) DDTCoumestrol
BPA 4-nonylphenol 17 B estradiol chlordecone Tributyltin Ah receptor model
Lessons learned- some too late Biology is conserved What can go wrong How disruption occurs New end points New mechanisms Indicators- the canary in the coal mine Need confirmation from mammalian data
Summary of lessons BirdsReproduction, development Behaviour PCB, TCDD, Cl- MammalsReproduction development Chlorinated chem.’s Fish Amphibian Sex determinationEE, E, T, A Invert.’scross species; growth, development Juvenile mimics; TBT;
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