Arsenic appears to suppress the ability of this critical receptor to respond to its normal hormone signal. Chemicals that disrupt steroid hormone receptor signaling are called endocrine disrupters. Arsenic, a metal, appears to act through a unique mechanism not previously shown for other endocrine disrupters such as pesticides. The Toxic Metals group is one of the interdisciplinary research projects associated with the Center for Environmental Health Sciences at Dartmouth, which Hamilton also directs. The work is funded by a grant from the National Institute of Environmental Health Sciences and the Environmental Protection Agency through the Superfund Basic Research Program.
Glucocorticoids are steroid hormones in the same class as estrogen, progesterone and testosterone.
Steroid hormones are chemical messengers secreted by glands into the bloodstream and carried to distant cells throughout the body where they help regulate the body's functions. Each hormone has a specific receptor it binds to in order to initiate its effects. Glucocorticoids, acting through their receptor, help regulate embryo development, stress, blood glucose levels, blood vessel function, and lung and skin development, and may also play a key role in suppressing cancer. Prior to this study, endocrine disrupting chemicals were thought to act primarily in one of two ways. One way is by binding to a steroid receptor and mimicking the normal hormone, leading to an inappropriate activation of the receptor.