Endocrine Abstracts

The Hypothalamic Pituitary Thyroid (HPT) axis is well-known as a classic endocrine negative feedback loop: increased levels of thyroxine (T4) in the blood are associated with a reduction of thyroid stimulating hormone (TSH) production and vice versa. However, the thyroid hormone (TH) system is sensitive to alterations by a number of endocrine disrupting chemicals (EDCs). Intriguingly, exposure to specific EDCs can decrease the levels of T4 but this might be not followed by the...

Certain endocrine disrupting chemicals (EDCs) are known to disrupt the thyroid hormone system. Thyroid hormone (TH) levels are physiologically regulated by the hypothalamic–pituitary–thyroid (HPT) axis, a tight feedback loop, whereby low levels of T4 stimulate an upregulation of TSH, and conversely if T4 levels are raised. Low levels of T4 (with chronic upregulation of TSH) can lead to thyroid hyperplasia – an outcome that is recognised by regulatory groups for ...