Objective: To investigate changes of bone morphogenesis proteins (BMP), transforming growth [correction of grouth] factors-beta (TGF-beta) in tibia and the growing of femur in tail-suspended rats after 21 d simulated weightlessness.
Method: Fourteen male SD rats were randomly divided into control group (CON) and tall-suspension group (TS). After 21 d tail-suspension, basic physical parameters of the femur were measured; changes of BMP, TGF-beta in tibia were assayed by immunohistochemical method.
Result: During 21 d tail-suspension, all rats grew well without apparent stress reaction. After 21 d weightlessness simulation, wet weight, dried weight, ash, diameter and density of femur in TS group declined significantly (P<0.01). Immunohistochemical results of tibia showed that both BMP and TGF-beta declined in tissues from all regions of the tibia.
Conclusion: After 21 d tall-suspension, the growth of rat's weight bearing bones were suppressed, production and secretion of BMP and TGF-beta was holdback.