Dioxin linked to reproductive disorder.
For the first time, researchers have connected the chemical TCDD, one of the most toxic members of the dioxin family, to endometriosis, a painful disease that affects an estimated 10 percent of women and can cause reproductive problems.
In a study of rhesus monkeys exposed to TCDD, Sherry E. Rier of the University of South Florida College of Medicine As of Fall 2006, there were 477 students in the M.D. program; 78 students in the M.S. and 83 students in the Ph.D. program in the School of Basic Biomedical Sciences; and 55 students in the DPT program in the School of Physical Therapy. in Tampa and her colleagues found that TCDD's effects on the body's hormonal and immune systems (SN: 1/11/92, p.24) may underlie the endometriosis-dioxin link, she says. "Chronic immunosuppression immunosuppression
Suppression of immunity with drugs, usually to prevent rejection of an organ transplant. Its aim is to allow the recipient to accept the organ permanently with no unpleasant side effects. in combination with hormonal dysregulation may have facilitated the aberrant growth of endometrial endometrial /en·do·me·tri·al/ (en?do-me´tre-il) pertaining to the endometrium.
n relating to the end-ometrium or cavity of the uterus. tissue" in the monkeys, the team writes in the November FUNDAMENTAL AND APPLIED TOXICOLOGY.
In endometriosis, endometrial cells grow outside their usual home in the uterus, form nodules Nodules
A small mass of tissue in the form of a protuberance or a knot that is solid and can be detected by touch.
Mentioned in: Leprosy in such places as the fallopian tubes or ovaries.
The study is "strongly supportive" of a link between TCDD exposure and the disease, says Linda S. Birnbaum, director of environmental Protection Agency Environmental Protection Agency (EPA), independent agency of the U.S. government, with headquarters in Washington, D.C. It was established in 1970 to reduce and control air and water pollution, noise pollution, and radiation and to ensure the safe handling and in Research Triangle Park Research Triangle Park, research, business, medical, and educational complex situated in central North Carolina. It has an area of 6,900 acres (2,795 hectares) and is 8 × 2 mi (13 × 3 km) in size. Named for the triangle formed by Duke Univ. , N.C.
Endometriosis had been found in rhesus monkeys exposed to polychlorinated biphenyls (PCBs) and to radiation. TCCD TCCD Training Course Control Document
TCCD Total Call Connection Delay , however, had not been implicated.
For four years beginning in 1978, Rier's group fed 14 monkets a TCDD-laced diet as part of a study on the health effects of that chemical. Autopsies on three monkeys that died between 1990 and 1992 uncovered endometriosis and prompted the researchers to examine the other animals.
The team found that five of the seven animals that had received a large dose of the chemical -- 25 parts of TCCDD per trillion parts of flood (ppt) -- developed moderate to severe endometriosis. There of the seven given 5 ppt of TCDD had moderate to severe disease. Other monkeys, including two of six fed a normal diet, developed a very mild form of the disease.
Stores of TCDD peaked at 100 to 800 parts per trillion in the body fat of the monkets, says Robert E. Bowman, a retired behavioral toxicologist and member of the study team. However, people and animals vary considerably in how much dioxin they store, he warns. At about 100 ppt of TCDD, monkeys "are getting into dangerous territory" regarding the risk of endometriosis, he says. The body fat of most humans contains about 7 ppt of TCDD, says Bowman.