Endocrine Disrupting Hormones

Question 1

What is an ECD?

Answer 1

• An ECD is a compound, either natural or synthetic, that alters hormonal and homeostatic systems within the body
• There is mounting evidence that ECDs can cause epigenetic changes which can be transmitted through generations
• Instead of a few dangerous chemicals EDCs may combine tiny effects to harm human health
• EDCs may have different effects at different concentrations
• Humans are most susceptible to damage by EDCs during neonatal/fetal development

Question 2

What is clover disease?

• What are its short term effects?
• What are its long term effects?

Answer 2

• Clover disease was a phenomenon observed in sheep in WA that were consuming large amounts of clover that was very high in phytoestrogens
• The short term effects caused reproductive issues including prolapse of uterus, altered cervical function, lactation, blocked urethra etc.
• The long term effects including irreversible fertility decline

Question 3

What is epigenetics?

Answer 3

• Epigenetic involves changes to DNA (including methylation) and histones resulting in the altered activity of genes (enhancement or silencing) without a change in DNA sequence
• Skinner et al studies showed that EDCs induced epigenetic changes in an exposed developing neonate (F1) and these changes (reduced fertility) were transmitted to future generations (F3)

Question 4

What are the foetal origins of adult disease?

Answer 4

• An adaption of the Barker hypothesis
• Disturbed endocrine exposure in utero has a negative influence of the development of the reproductive system and favours the occurrence of infertility and reproductive diseases in later adult life

Question 5

What are bisphenols?

Answer 5

• Bisphenols are estrogenic EDCs
• Found in plastics
• BPA is the most significant and has been banned in many countries
• The effects of BPA are especially significant in terms of exposure during fetal development
• Due to BPA banning BPF, BPS and BPAF have been generated however these molecules are also estrogenic

Question 6

What are Pthalates?

Answer 6

• EDC found in plastic

- Anti-androgenic (acts on ARs)

Question 7

What is Vinclozalin?

Answer 7

• EDC found in fungacide
• Anti-androgenic (acts on ARs)
• Metabolites can also act at progesterone receptors and ERs