Luteinizing Hormone Receptor Knockout (LuRKO) Mice and Transgenic Human Chorionic Gonadotropin (hCG)-Overexpressing Mice (hCG αβ+) Have Bone Phenotypes

• DOI: 10.1210/en.2003-0036
• Publication Date: 2003-05-13T05:35:17Z
• Authors: S. J. Yarram; M. J. Perry; T. J. Christopher; K. Westby; N. L. Brown; T. Lamminen; S. B. Rulli; F.-P. Zhang; I. Huhtaniemi; J. R. Sandy; J. P. Mansell
• Keywords: Gonadotropin; Human chorionic gonadotropin; Bone remodeling

Considerable attention has been paid to the role of sex steroids during periods major skeletal turnover, but interaction gonadotropic hormones, which include LH, FSH, and human chorionic gonadotropin (hCG), within bone tissue have overlooked. The question is pertinent due recent detection extragonadal expression receptors. Western blotting, immunolocalization, RT-PCR supported presence osteoblast LH However, cells failed bind [(125)I]hCG treatment with hCG generate either cAMP or phosphorylated ERK 1/2. Bone mineral density (BMD) histomorphometry were examined in following models: 1) receptor null mutant (LuRKO) mice; 2) transgenic mice overexpressing (hCG alphabeta+); 3) ovariectomized (OVX) alphabeta+ model. Male LuRKO showed a decrease BMD after 5 months, apparently secondary suppressed gonadal steroid production. Similarly, 9- 10-wk-old female exhibited decreases histomorphometric parameters tested. data indicate that loss signaling results reduction formation an increase resorption. By contrast, there significant increases indices for female, not male, mice, indicating chronic exposure OVX resulted comparable WT controls. Although levels are tightly linked titers, it appears their effects on skeleton indirect.