摘要
To investigate the significance of bone mineral changes in the pathogenic process of steroid-induced osteonecrosis in rabbits. Methods： Seventy adult female Japanese White rabbits were randomly divided into five groups Animals in steroid group received an intramuscular injection of methylprednisolone acetate （4 mg/kg） once a week, and killed in four different time after first treatment. Animals in control group received an intramuscular injection with the same volume of normal saline, while 150 kU penicillin was injected twice a week for preventing infection in all groups. The contents of serum calcium （Ca） and phosphorus （P） were determined and the bone mineral densities of the femoral head and neck were measured at the 2nd, 4th, 8th and 10th weeks after first treatment. Meanwhile the general condition such as weight, spirit and hair of rabbits was observed. Results： Compared with the control group, the weight of rabbits in steroid group lost since the first week, and progressively aggravated; the bone mineral density of the femoral head and neck was lowered since the 2nd and 4th week respectively （P〈0.05, P〈0.01）, and lowered more quickly in femoral neck than in femoral head. In steroid group, the bone mineral density of the femoral neck at the 10th week was significantly lower than that at the 8th week （P〈0.05） Compared with the control group, the serum levels of Ca and P in steroid group were lowered since the 2nd week （P〈0.05, P〈0.01）. In steroid group, the serum Ca level at the 10th week was lower than that at the 8th week, and the serum P level waslowered more quickly than Ca level was. Conclusion： Osteonecrosis appears in rabbits shortly after corticoids are first administered, and osteonecrosis in rabbits is chronologically associated with the onset of hypocalcaemia, hypophosphatemia and lowered bone mineral density. Steroid-induced osteonecrosis may be relevant to bone mineral loss and density lowering of the femoral head and neck.
Objective:To investigate the significance of bone mineral changes in the pathogenic process of steroid-induced osteonecrosis in rabbits. Methods:Seventy adult female Japanese White rabbits were randomly divided into five groups. Animals in steroid group received an intramuscular injection of methylprednisolone acetate (4 mg/kg) once a week, and killed in four different time after first treatment. Animals in control group received an intramuscular injection with the same volume of normal saline, while 150 kU penicillin was injected twice a week for preventing infection in all groups. The contents of serum calcium (Ca) and phosphorus (P) were determined and the bone mineral densities of the femoral head and neck were measured at the 2nd, 4th, 8th and 10th weeks after first treatment. Meanwhile the general condition such as weight, spirit and hair of rabbits was observed. Results:Compared with the control group, the weight of rabbits in steroid group lost since the first week, and progressively aggravated; the bone mineral density of the femoral head and neck was lowered since the 2nd and 4th week respectively (P<0.05, P<0.01), and lowered more quickly in femoral neck than in femoral head. In steroid group, the bone mineral density of the femoral neck at the 10th week was significantly lower than that at the 8th week (P<0.05). Compared with the control group, the serum levels of Ca and P in steroid group were lowered since the 2nd week (P<0.05, P<0.01). In steroid group, the serum Ca level at the 10th week was lower than that at the 8th week, and the serum P level waslowered more quickly than Ca level was. Conclusion:Osteonecrosis appears in rabbits shortly after corticoids are first administered, and osteonecrosis in rabbits is chronologically associated with the onset of hypocalcaemia, hypophosphatemia and lowered bone mineral density. Steroid-induced osteonecrosis may be relevant to bone mineral loss and density lowering of the femoral head and neck.
