甲基睾丸素、钙剂对损毁弓状核老年大鼠骨丢失的干预研究

目的：观察甲基睾丸素、钙剂对新生期损毁弓状核老年雄性大鼠的第三腰椎、股骨的体积骨密度，性激素水平及胫骨干骺端微结构变化的影响。方法：选用18只新生期雄性SD大鼠，按体重随机分成损毁弓状核老年大鼠组（MA）、自然衰老大鼠组（NA）、损毁ARC老年大鼠治疗组（MT），同等条件下饲养至820日龄，处死大鼠收集血清行T和E2放免检测，取左侧胫骨干骺端行骨组织切片及组织形态计量学分析等。结果：MA组大鼠L3、股骨的体积骨密度均下降，T和E2水平显著下降，与NA组比较差异有显著性意义（P〈0．05）。与MA组比较，MT组大鼠L3、股骨的体积骨密度、T和E2水平明显增加，胫骨干骺端％Tb．Ar、Tb．N、Tb．Th明显增加。结论：损毁弓状核的老年雄性大鼠骨丢失加速．提示下丘脑弓状核参与骨质疏松形成的调控，应用甲基睾丸素、钙剂可以阻止损毁弓状核老年大鼠骨丢失的发生。

Intervention of methyl testosterone and calcium carbonate on bone loss in elderly rats treated with MSG neonatally

Objective:To study the changes in bone mineral density(BMD) of femur, third lumbar vertebrae,and bone microstructure in pretibia metaphysis in neonatally MSG-treated male aged rats with methyl testosterone and calcium carbonate.Method:Eighteen newborn SD rats were randomly divided into control group,model group and treatment group. After surviving 820 days,the rats were killed and examined the changes of markers.Result:Compared with control group, the level of serum T and E2 in model group decreased significantly. The bone mineral density of femur and third lumbar vertebrae decreased evidently. Compared with model group, the level of serum T and E2 in treatment group increased significantly. The bone mineral density of femur and third lumbar vertebrae increased evidently, and the %Tb.Ar, Tb.N and Tb.Th of proximal tibial metaphysis(PTM) were significantly increased. Conclusion: The cause of accelerated bone loss in neonatally MSG-treated male aged rats attributes to the lesions of ARC,which suggests that the ARC participates in the regulation and control of bone metabolism.Methyl testosterone and calcium carbonate can prevent the bone loss in neonatally MSG-treated male aged rats.