摘要
本文研究低钙摄入、维生素D供给正常时幼鼠血中骨钙素水平,以了解低钙时成骨细胞活性。实验采用60只21～23日Wistar断乳幼鼠,随机分为四组:A组,正常钙与VitD摄X组;B组,中度低钙组;C组,重度低钙组;D组,VitD缺乏组。定期监测血25-(OH)D_3水平。于实验中期(3周),末期(6周)分别处死1/2幼鼠,取血与左股骨标本。测血骨钙素水平,以股骨钙与股骨长计算股骨含钙指数。实验建立低钙与低VitD动物模型。结果发现严重低钙幼鼠股骨生长显著落后,VitD缺乏幼鼠股骨生长与正常组相似。低钙与VitD缺乏幼鼠股骨含钙指数均明显低于正常组,低钙组更严重。低钙组幼鼠血骨钙素水平略高于正常组,VitD缺乏幼鼠血骨钙素有增高趋势;提示低钙时股骨增生的成骨细胞活性低下,VitD缺乏幼鼠骨生长受阻程度不如低钙组明显,推测VitD缺乏与低钙时对成骨细胞的作用机理不同。本文研究证实低钙对生长期骨骼的影响远远超过临床估计。
Osteocalcin is secreted by osteobiasts and is specific to bone,which is the marker of the formation of bone. This study presented the serum osteocalcin levels in the growing rats fed by low-calcium diet and normal vitamin D intake to demonstrate the osteoblast activeted during low-calcium intake.
60 Wistar weaning male rats were studied. All the animals were devided into 4 groups at ran-dom:group A,provided normal calcium and vitamin D intake,as control;group B,as midle calcium deficiency; group C, severe calcium deficiency; group D, vitamin D deficiency. Serum 25-OHD3 concentrations were measured regularly. Serum osteocalcin levels were measured. The index of femur calcium content were calculaded by the calcium weight and the length of the femur. The animal models of calcium and vitamin D deficiencies were builded during the experiment. Our results found that the femur growth retarded significantly in severe calcium deficiency. The index of both rats with calcium and vitamin D deficiencies were lower than that in the control,especially in the rats with calcium deficiency. Serum osteocalcin levels in the rats with calcium deficiency were higher than that in the control, suggesting the osteobiasts be inactivy. The degree of the bone growth retardation in the rats with vitamin D deficiency was much better than that in the rats with calcium deficiency,indicated that there are deferences of the mechanism between calcium and Vitanin D deficiencies on osteobiasts. Our finding showed calcium deficiency severely affected the growing bones.
