Abstract:

Objective The research aimed to investigate the effect of autophagy intervention on femoral head necrosis in rats with steroid⁃induced osteonecrosis of femoral head. Methods Eighteen SPF SD rats were randomly divided into three groups：model group（M），autophagic block group（M⁃3⁃MA）and autophagic activation group（M⁃Rap），and then they were treated with methylprednisolone，methylprednisolone + 3⁃methyladenine（3⁃ MA），methylprednisolone + rapamycin，respectively. After 8 weeks，blood samples were collected from abdominal aorta for determination of blood lipid and endothelial nitric oxide synthase（eNOS），nitric oxide（NO）and endo⁃ thelin⁃1（ET⁃1）content. After harvesting the rat femoral head，the expression of LC3Ⅱ/Ⅰ and p62 was detected by Western blot. Results The necrosis rate of femoral head in M，M ⁃3⁃MA and M ⁃Rap groups was 66. 67%， 100% and 33.33%. Compared with group M，the mean necrotic surface area of femoral head was larger in group M⁃3⁃MA and smaller in group M⁃Rap. The difference was statistically significant（P < 0.05）. Compared with group M，the LC3Ⅱ/Ⅰ expression in M⁃3⁃MA group was decreased and the expression of p62 was increased，the levels of TG，TCH，LDL and ET⁃1 in blood were all increased，but the contents of HDL，eNOS and NO were decreased； in M⁃RAP group，the expression of LC3Ⅱ/Ⅰ protein was increased，the expression of p62 protein was decreased， the levels of TG，TCH，LDL and ET⁃1 in blood were decreased，but the HDL，eNOS and NO increased. All the differences were statistically significant（P < 0.05）. Conclusion Autophagy intervention can improve the inci⁃ dence of SANFH by regulating lipid metabolism and promoting the repair of vascular endothelial injury，and limit the scope of necrotic lesions，which is a new direction of SANFH treatment.

Key words:

autophagy, steroid ? induced necrosis of femoral head, blood lipid, nitric oxide syn? thase, endothelin