对长期低钙摄入幼鼠骨骼的研究——Ⅱ低钙时幼鼠股骨生长板的病理变化

LIGHT-MICROSCOPIC OBSERNATION ON THE FEMUR CARTILAGE IN GROWING RATS FED BY MIDDLE AND SEVERE LOW-CALCIUM DIET

本文研究在VitD营养正常有不同程度低钙时对生长着幼鼠股骨生长板的生长、骨矿化、骨组织学的变化。实验采用21～23日龄Wistar断乳雄鼠45只。随机分为3组:A组,对照组,饲料含钙0.5％;B组,中度低钙(0.15％);C组,重度缺钙(0.03％)。于实验中期(3周)、末期(6周)分别处死1/2幼鼠,取左后肢股骨制成病理切片(4μm)。光镜下观察结果示B组中度低钙幼鼠股骨干骺端生长盘软骨显著厚于A组,尤以增生区和基质钙化区著;空泡细胞层显著增加6～14层(正常约4～5层);骨小梁粗乱;成骨细胞增生。C组重度缺钙幼鼠股骨干骺端生长板软骨增厚更加明显,空泡细胞层达7～12层,骨小梁周围有显著增生的成骨细胞。证实低钙时股骨干骺端生长板软骨有明显组织形态改变。低钙使长骨生长板软骨细胞肥大层增生增厚、成骨细胞增生,是否低钙使终末软骨细胞死亡减少,以及如何使成骨细胞生长调节异常尚待研究。

Previous studies demonstrated that the growing rats fed by low-calcium diet suf- fered from osteoporosis , and growth reardation . But there were few studies about the patho-physiology of bone, especially the relation bet wee the calcium nutrition and pathophysiology of bone. This study inverstigated the growth,mineralization and histological changes occuring in the growth plate of femur, 45 weaning male rats were studied. All the rats were devides into three groups:group A,as control ,0. 5% of calcium contained in the diet;group B,fed on middle low-calcium diet (0. 15%) ;group C,fed on severe low-calcium diet (0. 03%). The half of the rats were killed at the 3rd week and the 6th week during the experiment. The pathological samples were taken from the left femur. Under light - microscopic observation, the cartilage on the growht plate in the rats of grup B was the thicker than that in group A,especially in proliferative and the terminal chondrocyte (martix calcification ) zones, lightmicroscopy revelaed increasing vacuolation of the cells to 6-12 layers in group B. Trabecular bone volume spreaded disorderly . And increasing osteoblasts were observed. The cartilage on the growth plate in the rats of growp c presented thicken than that in group B,where the 7-14 layers of vacuolar cells and increasing the osteoblasts around the trabecular bone were showed. Our results demonstrated that the chon-drocytes on the femur growth plate in the rats fed by low-calcium diet presented the remarkably histological changes. The mechanism will be inverstigated further.