Endocrine Abstracts

The type 3 deiodinase enzyme (D3) inactivates T3 and prevents activation of T4 to protect the fetus from premature exposure to thyroid hormones. Rapidly falling levels of D3 activity and rising levels of T3 at birth initiate the onset of cell differentiation and organ maturation during the post-natal period. Congenital hypothyroidism causes delayed ossification with reduced bone mineral deposition and short stature. We hypothesize that increase...

Hypothyroidism and thyrotoxicosis have detrimental effects on skeletal development and adult bone strength. These effects result from thyroid hormone actions in bone, although a direct role for TSH in osteoblasts and osteoclasts was postulated following analysis of TSH receptor (TSHR) null mice. This hypothesis remains controversial as other studies failed to demonstrate osteoblast or osteoclast responses to TSH in vitro. Thyrostimulin is a heterodimeric glycoprotein ho...