Table 2. Summary of interactions among CaR, 1,25(OH)2D3, and PTH on mineral and skeletal homeostasis.
| CaR−/− | CaR−/−1α(OH)ase−/− | CaR−/−PTH−/− | |
| Changes of lifespan and bone weight | |||
| Lifespan | ↓↓↓ | ↓↓ | → |
| Body weight | ↓↓↓ | ↓↓ | → |
| Mineral ion homeostasis | |||
| Serum calcium | ↑↑↑ | → | → |
| Serum phosphorus | ↓↓ | ↓↓↓ | ↑ |
| Serum ALP | ↑↑ | ↑↑↑ | → |
| Serum PTH | ↑↑ | ↑↑↑ | — |
| Serum 1,25(OH)2D3 | ↑↑↑ | — | ↓ |
| Cartilage changes | |||
| Secondary ossification center | ↓↓↓ | ↓↓ | → |
| Width of growth plate | ↑↑↑ | ↑ | → |
| Chondrocyte proliferation | ↓↓↓ | ↓↓ | ↑ |
| PTHrP+ chondrocytes | ↓↓↓ | ↓↓ | ↑ |
| Bone changes | |||
| Trabecular bone volume | ↑↑ | ↑↑↑ | ↓ |
| Osteoblast production | ↑↑ | ↑↑↑ | ↓ |
| Bone mineralization | ↓↓↓ | ↓↓ | → |
| Osteoclast production | ↑↑ | ↑ | → |
↓, a reduction; ↑, an increase; →, no change. and —, undetectable. Repetitive arrows indicate the magnitude of the change.