Yamaguchi M, Kishi S, Hoshi T
Laboratory of Metabolism and Endocrinology, Graduate School of Nutritional Sciences, Japan.
Biol Pharm Bull. 1993 Nov;16(11):1179-81. doi: 10.1248/bpb.16.1179.
The effect of insulin administration on bone formation was investigated in the femoral diaphysis of rats with skeletal unloading. When the femoral-diaphyseal tissues from normal rats were cultured in the presence of insulin (10(-9) and 10(-8) M) for 48 h, the hormone produced a significant increase of alkaline phosphatase activity, collagen, deoxyribonucleic acid (DNA) and calcium contents in the bone tissues, indicating that it has a direct stimulatory effect on bone formation. Moreover, when normal rats received a subcutaneous administration of insulin (5.0 IU/100 g body weight) 5 times at 24-h intervals, the hormone caused a significant increase of alkaline phosphatase activity, DNA and calcium contents in the femoral diaphysis. Those increases were not seen by insulin administration to the skeletal-unloading rats with hindlimb hang for 4 d. The present results indicate that the stimulatory effect of insulin on bone formation is lost by skeletal unloading. The finding further supports the view that insulin impairment plays an important role in the deterioration of bone formation by microgravity.
在骨骼失用的大鼠股骨干中研究了胰岛素给药对骨形成的影响。当将正常大鼠的股骨干组织在胰岛素（10⁻⁹和10⁻⁸ M）存在的情况下培养48小时时，该激素使骨组织中的碱性磷酸酶活性、胶原蛋白、脱氧核糖核酸（DNA）和钙含量显著增加，表明它对骨形成具有直接刺激作用。此外，当正常大鼠以24小时间隔皮下注射胰岛素（5.0 IU/100 g体重）5次时，该激素使股骨干中的碱性磷酸酶活性、DNA和钙含量显著增加。对后肢悬吊4天的骨骼失用大鼠注射胰岛素未观察到这些增加。目前的结果表明，骨骼失用会使胰岛素对骨形成的刺激作用丧失。这一发现进一步支持了胰岛素损伤在微重力导致的骨形成恶化中起重要作用的观点。
