糖尿病性骨质疏松模型雌激素、一氧化氮及转化生长因子β1的变化

背景：糖尿病和卵巢去势是骨质疏松发生的两大主要原因,均会出现一氧化氮和转化生长因子β1的变化。 目的：探讨雌激素、一氧化氮、转化生长因子β1在糖尿病性骨质疏松模型中的变化及意义。 方法：采用链脲佐菌素诱导制备糖尿病大鼠模型,于造模后4,8,12,16周,进行骨密度检测,并应用放免法检测血清雌激素水平,硝酸还原酶法检测血清一氧化氮水平,ELISA法检测血清转化生长因子β1水平,免疫组织化学法检测骨中转化生长因子β1水平。 结果与结论：随着链脲佐菌素诱导时间的延长,糖尿病大鼠股骨骨密度逐渐降低(P < 0.05或P < 0.01);血清一氧化氮水平逐渐降低(P < 0.05或P < 0.01);血清转化生长因子β1水平逐渐升高(P < 0.01);血清雌激素水平轻度降低,与同时间点正常大鼠比较差异无显著性意义(P > 0.05)。免疫组织化学结果显示转化生长因子β1主要表达于成骨细胞的胞浆中,其阳性表达随链脲佐菌素诱导时间的延长逐渐下降(P < 0.01)。说明糖尿病大鼠血清一氧化氮水平和骨组织中转化生长因子β1水平的变化导致了骨吸收增加,骨形成减少,使骨密度降低,参与了糖尿病性骨质疏松的发生。

Changes of estrogen,nitric oxide and transforming growth factor beta 1 in rats with diabetic osteoporosis

BACKGROUND:Diabetes mellitus and ovariectomy are two main reasons for osteoporosis, both of which can lead to variations in nitric oxide (NO) and transforming growth factor β1 (TGF-β1). OBJECTIVE: To study the changes of estrogen, NO, and TGF-β1 in the rats with diabetic osteoporosis. METHODS:Rats with diabetic osteoporosis were induced by streptozotocin (STZ). The bone mineral density (BMD) was measured at 4, 8, 12 and 16 weeks after model preparation; the serum estrogen levels was measured by radioimmunoassay method, serum NO levels ere detected by nitrate reduction method, serum TGF-β1 levels determined by ELISA method, and the content of TGF-β1 in the bone tissues was measured by the immunohistochemical method. RESULTS AND CONCLUSION:With induction time prolonged, BMD of femur was gradually decreased (P < 0.05 or P < 0.01), serum NO level decreased (P < 0.05 or P < 0.01), serum TGF-β1 level increased (P < 0.01). The estrogen level in the model group was slightly decreased, but the difference had no significance (P > 0.05). Immunohistochemical results showed that TGF-β1 was mainly expressed in the osteoblast cytoplasm, and the number of positive cells was gradually decreased with induction time prolonged (P < 0.01). The changes of serum NO and TGF-β1 in bone tissues result in lower bone mineral density because of increasing bone absorption and decreasing bone formation. Nitric oxide and TGF-β1 play an important role in diabetic osteoporosis.