If a patient with iodine deficiency receives a fixed dose of exogenous T4, which consequence follows regarding T3 production?

💡 Explanation

Peripheral conversion of T4 to T3 relies on deiodinase enzymes, which require selenium as a cofactor. Iodine deficiency often coexists with selenium deficiency, therefore the deiodinase enzymes are less effective and conversion is impaired, rather than being enhanced or fully compensated. Thus, even with T4 supplementation, T3 production remains suppressed.

• If a patient experiences increased interstitial fluid pressure within tissues surrounding a surgical wound, which consequence is most likely regarding lymphatic drainage?
• Why does rapid intravenous administration of a hypertonic glucose solution induce cellular dehydration in the digestive tract's epithelial cells?
• A researcher investigates fever reduction in mice using a novel drug. If this drug inhibits phospholipase A2 (PLA2) activity in hypothalamic cells, which consequence follows?
• If a genetically predisposed individual encounters a novel environmental antigen, which consequence relating to the immune system is most likely to drive an autoimmune response?
• Why does hypothyroidism often persist in patients with sufficient iodine intake after thyroidectomy, despite TSH stimulation?
• If a patient's liver develops cirrhosis due to chronic hepatitis C, which consequence follows regarding blood flow?