Regulation Of Nitric Oxide On The Biological Behaviour Of Rabbit Annulus Fibrosus Cell In Vitro

Objective: To investigate the regulatory effects and mechanism of nitric oxide on the biological behaviour of rabbit annulus fibrosus(AF) cells in vitro.Methods: Rabbit AF cells gel culture model was adopted in this study. Cultured AF cells were divided into 7 groups, and various concentrations of Sodium Nitroprusside (SNP) and iNOS inhibitors (Niacinamide and 1400W) were added to the medium for intervention. After 3 days of intervention, AF cell proliferation, apoptosis, mitochondrial membrane potential and the gene expressions of aggrecan, typeâ… andâ…¡collagen in each group were determined respectively by MTT assay, Annexin V-PI staining, mitochondrial membrane potential JC-1 staining and RT-PCR detection.Results:â‘ The absorbance(A) of MTT assay in group 3 and 4 were decreased significantly as compared with the normal control group(P<0.05,P<0.05), while the A of group 5, 6 and 7 were markedly higher than that of group 3(P<0.05,P<0.05,P<0.05).â‘¡Flow cytometry analysis showed the apoptotic ratio of group 2, 3 and 4 were far higher than that of the normal control group, in which the apoptotic ratio of group 4 was 32.98%; while the apppoptotic ratio of group 5, 6 and 7 were decreased significantly as compared with group 3, but remained higher than that of the normal control group.â‘¢Fluorospectrophotometer analysis showed the red/green fluorescence ratio of group 2, 3 and 4 were obviously lower than that of the normal control group(P<0.05, P<0.05, P<0.05), while the red/green fluorescence ratio of group 5, 6 and 7 were higher than that of group 3 and 4(P<0.05,P<0.05,P<0.05).â‘£RT-PCR showed the gene expressions of aggrecan, typeâ… a ndâ…¡collagen in group 2, 3 and 4 were significantly lower than that of the normal control group(P<0.05, P<0.05, P<0.05), while the gene expressions of aggrecan, typeâ… andâ…¡collagen in group 5, 6 and 7 were markedly increased as compared with group 3(P<0.05, P<0.05, P<0.05).Conclusions: NO has a strong ability of disturbing the biological behavior of rabbit AF cells, which maybe plays an important role in the AF injuried-mechanism. Inhibitors of iNOS can alleviate the disturbing effects of NO on biological behaviors of rabbit AF cells effectively, which are thought to possess the favorable potential for prevention and treatment of intervertebral disc degeneration.