|
Objective: To establish hormonal avascular necrosis animal model to investigate the pathogenesis of steroid-induced osteonecrosis mechanism; model after using hyperbaric oxygen therapy, hyperbaric oxygen therapy study of femoral head necrosis of possible mechanisms. Methods: Adult 60 Japanese white rabbits were randomly divided into model group and control group. Model group twice a week intramuscular prednisolone 10mg/kg, 2 times a week intramuscularly control group saline 2ml / only, model group after 6 weeks of treatment rabbits were randomly divided into treatment group and control group. Control group breathing atmospheric air. Hyperbaric oxygen therapy in the treatment group, 1 times / d, a course of two weeks, a total of three courses. Observed before the experiment and experimental animals after 2,4,6,8,10,12 weeks hemorheology, serum total cholesterol (TC), triglyceride (TG) changes, and the femoral head specimens were stained with HE , transmission electron microscopy and immunohistochemical staining of VEGF and other observations. Results: The experimental group 2,4,6 weeks TG, TC, whole blood viscosity, plasma viscosity higher. Femoral osteoporosis model group, model group, light microscopy shows femoral trabecular bone thinning, empty lacunae increased, reducing the number of osteoblasts. TEM observation showed that part of the model group femoral head bone cell shrinkage, nuclear condensation, more bone cells have necrolysis pieces and observed a greater osteoblast apoptosis, VEGF-positive reduction in the rate of osteoblasts. Treatment group TG, TC, whole blood viscosity, plasma viscosity decreased, HE staining surrounding trabecular osteoblasts, osteoclasts hyperplasia, hypertrophy of fat cells decreased bone marrow cavity, hematopoietic tissue, electron microscopy findings appeared in trabecular bone immature bone cells, collagen synthesis, and visible new capillaries, VEGF-positive osteoblasts rate increased. Conclusion: a large dose of hormones can lead to avascular necrosis in rabbits; 2. Hyperviscosity and rheology of femoral head necrosis factor in the pathogenesis may play an important role; 3 bone necrosis and steroid-induced apoptosis in the pathogenesis of osteonecrosis development process may play an important role; 4 femoral head necrosis by hyperbaric oxygen therapy helps bone tissue repair. The mechanism may be that the high oxygen partial oxygen tension increase femoral head, to promote the establishment of collateral circulation, improve local tissue ischemia, increased fibroblast, osteoblast, osteoclast activity, and promote the secretion of cytokines such as VEGF, thereby necrosis of the femoral head accelerate tissue repair.
|