Abstract:

BACKGROUND: Previous research has demonstrated that pravastatin promoted the repairing of steroid-induced femoral head necrosis via up-regulating expressions of endogenous bone morphogenetic protein-2, core-binding factor-α1, and vascular endothelial growth factor.
OBJECTIVE: To evaluate the histological changes of a rabbit model of steroid-induced femoral head necrosis intervened by pravastatin using general observation and light microscope.
METHODS: A total of 80 New Zealand white rabbits were randomly divided into normal control group (n=18) and experimental group (n=62). The experimental group was injected with escherichia coli endotoxin (10 μg/kg) into auricular vein twice, every 24-hour intervals; while, prednisolone (20 mg/kg) was injected into buttock three times, every 24-hour intervals to make steroid-induced femoral head necrosis model. At the fifth week, 36 out of 39 rabbits were equally divided into model group and pravastatin group. The pravastatin group was intragastrically administrated with pravastatin (1.2 mg/kg), once a day. Model and control groups were intragastrically administrated with the equal volume of saline. The femoral head was obtained at 8, 12, and 16 weeks and observed with general observation and light microscope.
RESULTS AND CONCLUSION: Gross observation and light microscopy demonstrated that a clear bone necrosis of femoral head was observed in the model group, and a large number of fat cell proliferation was found in the bone marrow cavity. As compared with model group, injured level of cells in the pravastatin group was mild, density of bone trabecula was high, ratio of bone lacuna was less, area of bone necrosis was decreased, number of adipocytes was reduced, and bone necrosis was well repaired. This suggested that pravastatin could effectively restore steroid-induced femoral head necrosis in the early stage.