Related Experiment Video
Updated: Mar 3, 2026

Author Spotlight: In Vivo Assessment of Thyroid Hormone Disruption Using the THAI Mouse Model
Published on: October 6, 2023
Erythrocyte hemoglobin A2 (Hb A2) was quantitated in 28 hyperthyroid patients prior to antithyroid therapy and at intervals during therapy. Fetal hemoglobin (Hb F) levels and red cell mean corpuscular volume (MCV) were also monitored. Before therapy, Hb A2 was significantly elevated (mean +/- SD, 3.3 +/- 0.5%: normals, 2.5 +/- 0.3%: p less than 0.001). Hb F levels exceeded 1.0% in 10 cases. A tendency to red cell microcytosis was also observed (mean MCV 81.1 fl). To-date 10 of these subjects have had adequate studies following appropriate and sustained responses to antithyroid therapy. All showed a fall in Hb A2, usually accompanied by a rise in red cell MCV. A hematologic profile for hyperthyroidism is proposed.
Erythrocyte hemoglobin A2 (Hb A2) was quantitated in 28 hyperthyroid patients prior to antithyroid therapy and at intervals during therapy. Fetal hemoglobin (Hb F) levels and red cell mean corpuscular volume (MCV) were also monitored. Before therapy, Hb A2 was significantly elevated (mean +/- SD, 3.3 +/- 0.5%: normals, 2.5 +/- 0.3%: p less than 0.001). Hb F levels exceeded 1.0% in 10 cases. A tendency to red cell microcytosis was also observed (mean MCV 81.1 fl). To-date 10 of these subjects have had adequate studies following appropriate and sustained responses to antithyroid therapy. All showed a fall in Hb A2, usually accompanied by a rise in red cell MCV. A hematologic profile for hyperthyroidism is proposed.
Related Concept Videos
Pharmacogenetics of Drug Targets: β₂-Adrenergic Receptors, Apo E, Thymidylate Synthase
Synthesis and Regulation of Thyroid Hormones
Upon reaching the thyroid gland, TSH stimulates the follicular cells' active uptake of iodide ions from the blood. The ions diffuse to the apical surface of the cells and are oxidized to iodine. The...
Disorders of Erythrocytes
Erythrocyte disorders can be broadly categorized into two main types: anemic and polycythemic conditions.
A low oxygen-carrying capacity of the blood due to the loss, lower production, or destruction of erythrocytes is termed anemia. Hemorrhagic anemia, for example, occurs when bleeding from an external wound or internal ulcer reduces erythrocyte counts.
On the other...
Functions of Thyroid Hormones
TH is indispensable for the normal development and maturation of the skeletal, muscular, and nervous systems during fetal and childhood growth. It facilitates bone mineral turnover and regulates protein synthesis in developing tissues, contributing significantly to overall growth and...
Hemoglobin
When all four heme groups are bound to oxygen, the resulting molecule is called oxyhemoglobin. As a result, arterial blood...
The Thyroid Gland
The follicles have a central cavity lined by simple cuboidal to squamous epithelial cells called follicular cells. These cells produce the glycoprotein...

