Question

Propylthiouracil (PTU) is a drug that inhibits the production of thyroxine by blocking the attachment of iodine to tyrosine residues in the follicle cells of the thyroid gland (iodinated tyrosines are linked together to form thyroxine). What do you think will happen after you inject PTU into the three rats?

Answer 1

Injecting PTU into rats will inhibit the production of thyroid hormones T3 and T4, leading to a decrease in the metabolic rate.

Step-by-step explanation:

When propylthiouracil (PTU) is injected into rats, it inhibits the production of thyroxine (T4) by blocking the attachment of iodine to tyrosine residues in the follicle cells of the thyroid gland. This prevents the synthesis of T4, which is the precursor to the active thyroid hormone triiodothyronine (T3). As a result, the rats will have reduced levels of T3 and T4 in their bloodstream. This can lead to a decrease in the metabolic rate and various symptoms related to an underactive thyroid.