Estradiol Alleviates Intervertebral Disc Degeneration through Modulating the Antioxidant Enzymes and Inhibiting Autophagy in the Model of Menopause Rats

Figure 2

(a) Histological illustration of the L5–L6 IVDs 3 months postsurgery (original magnification, 4x). The arrows indicate the certain cell types in the NP tissue (red arrows: notochord cells; black arrows: chondrocyte-like cells; original magnification, 20x). (b) Ectopic bone tissue in EP. (c) Safranin-O (S-O) staining and picric acid-sirius red (P-R) staining of the IVD (original magnification, 4x). The red staining intensity for proteoglycan decreased in the NP and AF tissue with ovariectomy; estrogen supplementation can reverse the degeneration changes; collagen II was mainly displayed in the inner AF of the sham and OVX + E2 groups, but it was replaced by collagen I in the OVX group. (d) Histological score of disc degeneration of the three groups ( compared with the sham group and OVX + E2 group).

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