[Effects of DDT and lindane on thyroid function in the rat]

Area of Science:

• Endocrinology
• Toxicology
• Environmental Health

Background:

• Pesticide exposure can disrupt endocrine function.
• Understanding the impact of DDT and lindane on thyroid hormones is crucial for public health.

Purpose of the Study:

• To investigate the effects of DDT and lindane on iodine and hormone metabolism in rats.
• To compare the efficacy of DDT and lindane in altering thyroid function.

Main Methods:

• Rats were administered daily doses of DDT (30 and 75 mg/kg) and lindane (12 and 36 mg/kg).
• Iodine-131 labelled NaI was used to track iodine and hormone metabolism.
• Thyroid mass, iodine levels, and serum/liver hormone concentrations were measured.

Main Results:

• DDT increased thyroid mass, thyroid tri-iodothyronine (TT3) and thyroxine (T4) levels, while decreasing thyroid iodine.
• DDT reduced serum iodine and protein-bound iodine, with slight increases in serum T4 and marked increases in serum TT3.
• Lindane showed less pronounced effects, with a decrease in thyroid TT3 and an increase in thyroid T4, while serum hormones remained unchanged.

Conclusions:

• DDT significantly impacts rat iodine and hormone metabolism, affecting thyroid function and hormone levels.
• Lindane exhibits considerably weaker effects on thyroid hormone metabolism compared to DDT.
• The observed effects of these pesticides are complex, highlighting potential risks to endocrine health.