| Objective To investigate the effect of different exercise intensity on ovariectomized osteoporosis SD rats and its effect on cartilage morphology. Methods From September 2017 to November 2018, 40 SD rats were taken from the central laboratory of the Third Affiliated Hospital of Sun Yat-sen University as a research object. The rat osteoporosis model was established by cutting off the oviduct and removing the ovaries. Ten SD healthy rats in the same period were taken as the sham group. According to the different treatment methods, rats were divided into model control group, low intensity group, medium intensity group, and high intensity group, with 10 rats in each group. Rats in the model control group were routinely fed. Rats in the low-intensity group, the medium-intensity group, and the high-intensity group were trained for 10 m/min, 20 m/min, or 25 m/min, respectively, 1 h per day for 6 weeks. The arterial cartilage Mankin score, articular cartilage thickness, serum levels of calcium, phosphorus, and MMP-3, HE and saffron staining were compared between the different groups after 6-week of the treatment. Results 1) The simple mental state evaluation (MMS) score in the moderate intensity group was lower than that in the low intensity group, the high intensity group, and the model control group (P<0.05). The MMS score in the low intensity group was lower than that in the high intensity group and the model group (P<0.05). The thickness of articular cartilage in the moderate intensity group was higher than that in the low intensity group, the high intensity group, and the model control group (P<0.05). 2) The serum levels of calcium and serum phosphorus in the medium intensity group were lower than those in the low intensity group, high intensity group, and model control group (P<0.05). 3) The cartilage in the model control group had smooth surface and round or elliptical shape. In low-intensity group, human cartilage surface was relatively smooth, the number of cells was relatively large, and the arrangement was regular and the staining was deepened. In the middle load exercise group, the cartilage surface was smooth, the staining was obviously thickened, the matrix staining was deep, and the staining was uniform. The cartilage in the high-intensity group had irregular tide lines and the staining was relatively shallow. Conclusion Moderate exercise intensity is ideal for ovariectomized osteoporosis rats. |