Table 2. Summary of Inhibin and Activin Effects on Bone Cells.
| Model | Activin A effects | Inhibin A/B effects | References |
|---|---|---|---|
| In vitro models | |||
| Fetal rat Calvaria (FRC, digests 3-5) | ↑ OB | NR | (Centrella, 1991) |
| Fetal rat Calvaria (FRC, digest 3) | ↓ mineralization | NR | (Ikenoue, 1999). |
| Murine bone Marrow cultures | ↑ OB AP+ CFU-F, CFU-OB, ↑ TRAP+ OCL | ↓ AP+ CFU-F, CFU-OB, ↓ TRAP+ OCL | (Gaddy-Kurten, 2002) |
| Human PBMCs | ↑TRAP+ OCL | ↓TRAP+ OCL | (Eijken, 2007; Perrien, 2006; Fuller, 2000) |
| Human mesenchymal stem cells | ↓AP+ cells, Mineralization | ↓ AP+ cells, Mineralization | (Eijken, 2007; Perrien, 2006) |
| Human fetal osteoblasts | ↓AP+cells, Mineralization | NR | (Eijken, 2007) |
| In vivo models | |||
| Local injection over neonatal calvaria | ↑ bone formation (rat) | NR | (Oue, 1994) |
| Systemic administration in intact rodents | ↑ bone formation (rat) | ↑ bone formation (mouse) | (Sakai, 2000; Perrien, 2007) |
| Systemic administration in gonadectomorized rodents | ↑ bone formation (rat) | ↑ bone formation (mouse) | (Sakai, 2000; Perrien, 2007) |
| Local injection at fracture site | ↑ bone formation (rat) | NR | (Sakai, 1999) |
| Clinical correlations | |||
| Bone formation marker levels | NR | Serum Inhibins inversely correlated | (Perrien, 2006) |
| Bone resorption marker levels | NR | Serum Inhibins inversely correlated | (Perrien, 2006; Vural, 2005) |
| Bone mass | NR | Serum Inhibins inversely correlated | (Vural, 2005) |
PBMC, peripheral blood mononuclear cells; OB, osteoblastogenesis; OCL, osteoclastogenesis; AP+, alkaline phosphatase positive; CFU-F, colony forming unit-fibroblast; TRAP+, tartrate resistant acid phosphatase positive; NR, Not Reported