How thyroid hormones affect bone cells
Thyroid hormone stimulates alkaline phosphatase activity in cultured rat osteoblastic cells (ROS 17/2.8) through 3,5,3'-triiodo-L-thyronine nuclear receptors.
Not medical advice. For informational purposes only. Always consult a healthcare professional. Terms
Surprising Findings
Thyroid hormones stimulate bone cell enzyme activity at extremely low (physiologically relevant) concentrations
It was not previously confirmed whether such tiny amounts of T3 and T4 — levels actually seen in human hyperthyroidism — could directly affect bone cells. The fact that they do, via nuclear receptors, shows a highly sensitive and specific system.
Practical Takeaways
If you have hyperthyroidism and elevated alkaline phosphatase, discuss bone health with your doctor — it might reflect increased bone turnover, not liver problems.
Not medical advice. For informational purposes only. Always consult a healthcare professional. Terms
Surprising Findings
Thyroid hormones stimulate bone cell enzyme activity at extremely low (physiologically relevant) concentrations
It was not previously confirmed whether such tiny amounts of T3 and T4 — levels actually seen in human hyperthyroidism — could directly affect bone cells. The fact that they do, via nuclear receptors, shows a highly sensitive and specific system.
Practical Takeaways
If you have hyperthyroidism and elevated alkaline phosphatase, discuss bone health with your doctor — it might reflect increased bone turnover, not liver problems.
Publication
Journal
Endocrinology
Year
1987
Authors
K. Sato, D. Han, Y. Fujii, T. Tsushima, K. Shizume
Related Content
Claims (5)
When someone has an overactive thyroid, their high alkaline phosphatase levels are usually because of faster bone turnover, not liver problems — thyroid hormones speed up how bones break down and rebuild.
Thyroid hormone might directly boost a bone enzyme in lab-grown rat bone cells at levels seen in people with an overactive thyroid, which could explain why those patients often have high bone enzyme levels.
Thyroid hormones seem to turn up the activity of a bone-building enzyme in rat bone cells, even at low levels—kind of like a volume knob for bone growth.
Rat bone-building cells have special spots inside their control centers that grab thyroid hormone very tightly, and each cell has room for about 2,000 of these hormone connections.
In rat bone cells, how strongly different thyroid hormones stick to their receptors matches how active they're known to be — suggesting these receptors actually do something important in how thyroid hormones affect bones.