Fig. 7

Histology of the rabbit nucleus pulposus (NP) after lumbar artery ligation. Notochordal cells were embedded in a gelatinous matrix that was uniformly stained with Safranin-O in the NP of sham-operated rabbits (Sham-OP) (0 W) discs (a, b, c, d). Safranin-O staining properties changed after ligation of lumbar arteries. At 4 weeks (f, g, h) and 8 weeks (j, k, l), the staining patterns were irregular, and intense staining is seen in the pericellular matrix. At 12 weeks (N, O, P), an irregular staining pattern remained. L2/L3 discs (e, i, m) were used as controls