Endocrine Abstracts

T3, GH and IGF-1 are essential for skeletal development. GH acts directly on growth plate chondrocytes and also via a local paracrine pathway involving IGF-1, but it is unclear whether T3 stimulates bone formation directly or indirectly. To address this, we determined expression of GH-receptor, IGF-1 and IGF-1 receptor (IGF-1R) by in situ hybridisation and activation of downstream STAT5 and AKT signalling by immunohistochemistry in growth plates from four T3-receptor (TR) muta...

T3, GH and IGF-1 are essential for skeletal development, growth and bone mineralisation. The major growth-promoting actions of GH occur in epiphyseal chondrocytes via direct effects on GH-receptor expressing cells and via a local paracrine pathway involving IGF-1. There is controversy regarding whether T3-actions in bone are direct or occur via regulation of GH secretion and action. We examined this in mice with a mutation (PV) targeted to either T3-receptor (TR) beta or alpha...