Hormones and Health

1
Hormones and Health

• Article by Mary W. Eubanks
• Intro to Environmental Science
• Presentation by Tina Irwin

2
History

• 1967 Rachel Carsons Silent Spring
• 1996 Our Stolen Future by Theo Colborn, Dianne
  Dumanoski, and John Myers
• Recent advances in technologies

3
Whats all the fuss about the Endocrine System?

• Regulates all responses and functions of the body
  
• Provides cellular instructions via chemical
  messengers
• Ex. Hormones cause dramatic changes in cellular
  activity by extremely small amounts of chemical

4
Endocrine Glands

• Pituitary
• Thyroid
• Parathyroid
• Adrenal
• Pancreas
• Pineal Gland
• Gonad

5
Whats a target cell?

6
Androgens and Estrogens

• Steroids that are fat-soluble and pass through
  the plasma membranes of their target cells
• Testosterone and androsterone in males
• Estrogens and progesterone in females

7
Hormone Regulation

• Negative feedback loop http//www.vivo.colostate.e
  du/hbooks/pathphys/endocrine/basics/control.html

• Turned off and on in response to fluctuating
  hormone levels
• Commanded by hypothalamus

8
Hormonal Carcinogenesis

• Sex hormones and other steroids alter gene
  expression in target cells
• Toxics may compete with hormones and take up
  receptor sites

9
Research

• Estrogen has been found to induce tumor formation
  in various organs and tissues
• Noble rats have been used to study the role of
  free radicals in initiating prostate tumors
• Androgen production declines with age but
  estrogen levels remain the same

10
Hormonal Disruptors

• Environmental chemicals exhibit estrogenic
  activity
• Example Lake Apopka, FL

11
What now?

• Low incidences of cancers in certain populations
  with diets rich in phytoestrogens
• Ex. Asians
• Scientists are exploring risk factors from
  exposure to promote debate and generate public
  policy in regard to use and distribution of
  chemicals in the environment

12
Bibliography

• Eubanks, Mary W. Hormones and Health.
  Environmental Health Perspectives. Volume 105,
  Number 5, May 1997.
• The Florida Times
• http//www.jacksonville.com/tu-online/stories/0227
  99/met_2a1apopk.html