Endocrine Abstracts

Thyroid hormones thyroxine and triiodothyronine are essential for development, growth and metabolism. The prohormone thyroglobulin (Tg) is stored in high concentrations and in covalently cross-linked form within the lumen of thyroid follicles. Thyroid hormones are liberated from Tg in a regulated manner in that TSH triggers the secretion of lysosomal enzymes into the extracellular follicle lumen where they solubilize covalently cross-linked Tg and liberate thyroxine by partial...