Question

What is the function of reverse triiodothyronine?

Answer 1

Question #61719, Biology, Human Anatomy and Physiology

What is the function of reverse triiodothyronine?

Answer:

Reverse triiodothyronine (3,3',5'-triiodothyronine, reverse T₃, or rT₃) is an isomer of triiodothyronine (3,5,3' triiodothyronine, T₃). It is a type of hormone that is produced by the thyroid gland. It comes from the conversion of the storage hormone T4.

Reverse triiodothyronine participate in regulating metabolism.

In particular, there are many different situations in which reverse triiodothyronine levels may be raised. It is known that, in the fetus, larger amounts of reverse T3 are created, together with lower levels of triiodothyronine. Levels of reverse T3 drop several weeks after birth to match those of normal adults. Fasting initially causes a fall in T3 and an increase in reverse T3, while longer-term starvation sees reverse triiodothyronine levels returning to normal. Overeating has the opposite effect, with a rise in T3 and a decrease in rT3.

Certain drugs can affect deiodinase enzymes, inhibiting their actions and leading to a decrease in the conversion of T4 to T3 in the body's tissues, and a deficiency of selenium can have a similar effect. In what is referred to as euthyroid sick syndrome, serious illnesses such as cancer, kidney and liver failure, heart attacks, infections and burns suppress deiodinase enzymes. This means that it can be difficult to assess thyroid function in people who are gravely ill, as the levels of thyroid hormones may be abnormal in the absence of thyroid disease. In euthyroid sick syndrome, even though the amount of T3 produced by the thyroid gland remains the same, decreased conversion in the tissues causes a reduction in the overall level of T3. Less reverse T3 is cleared from the body, with the result that reverse triiodothyronine levels increase.

https://www.AssignmentExpert.com