一氧化氮合酶抑制剂对延缓腰椎间盘退变的影响

Potential clinical evaluation of nitric oxide synthase inhibitor for the treatment of lumbar intervertebral disc degeneration

目的 探讨一氧化氮合酶(NOS)抑制剂L N6 亚氨乙基 赖氨酸(L NIL)和S 甲基异硫脲(SMT)对退变腰椎间盘组织代谢的影响。方法 无菌条件下,取2 0例腰椎间盘突出症患者的椎间盘组织体外培养,分别加入1mmol/L浓度的SMT和L NIL ,培养72h后,通过检测硝酸盐和亚硝酸盐的含量来观察椎间盘NO的释放量及NOS的活性;原位杂交法检测椎间盘组织iNOSmRNA和MMP3mRNA的表达。培养10d后,化学比色法观察椎间盘蛋白多糖含量和羟脯氨酸释放量的变化。结果 L NIL组髓核和纤维环NO释放量(65 .6±4.5 ,68.8±5 .7) μmol/L和SMT组髓核和纤维环NO释放量(69.5±6.5 ,69.1±6.1) μmol/L较对照组NO释放量(10 7.9±4.4,93 .1±5 .9) μmol/L明显减少(P <0 .0 1)。L NIL组和SMT组髓核组织中蛋白多糖含量(5 1.3±9.6,48.2±8.5 )kg/L ,比对照组(3 2 .1±6.4)kg/L明显增加(P <0 .0 1) ,羟脯氨酸释放量(1.1±0 .4,1.2±0 .5 )kg/L比对照组(3 .4±0 .8)kg/L显著减少(P <0 .0 1) ;同时,原位杂交法未检测到iNOSmRNA和MMP3mRNA的表达。结论 NOS抑制剂L NIL和SMT能抑制过量NO的释放。

Objective To discuss the metabolic effects on degenerative lumbar intervertebral disc by NOS inhibitor L-N6-(sub-amonion-ethyl) lysine (L-NIL) and S-methylisothiourea (SMT).Methods Twenty degenerative lumbar intervertebral discs were obtained from patients undergoing disc surgery.The specimens were cultured and divided into three groups.L-NIL and SMT group were interfered with NOS inhibitor L-NIL and SMT respectively.After 72 h culture,the release of NO and the activity of NOS in culture media were measured by Griess reaction and spectrophotometric methods.iNOSmRNA and MMP3 mRNA expression was detected by in situ hybridization.Proteoglycan and hydroxyproline in these specimens was measured with colorimetric analysis after 10 day culture.Results The NO concentration of nucleus pulposus (NP) and anulus fibrosus (AF) in L-NIL groups [(65.6± 4.5, 68.8± 5.7) μmol/L respectively] and in SMT groups [(69.5± 6.5 69.1± 6.1) μmol/L respectively] were significantly less than that in control groups [(107.9± 4.4, 93.1± 5.9) μmol/L respectively].The proteoglycan contents of NP in L-NIL and SMT groups [(51.3± 9.6, 48.2± 8.5) kg/L respectively] were significantly more than those in control groups [(32.1± 6.4) kg/L, P < 0.01]. Hydroxyproline release in L-NIL and SMT groups [(1.1± 0.4, 1.2± 0.5) kg/L repectively] was markedly less than that in control group [(3.4± 0.8) kg/L, P < 0.01]. Both L-NIL and SMT evidently inhibited completely iNOSmRNA and MMP3mRNA expression.Conclusion NOS inhibitors can reduce NO release and retard the process of lumbar intervertebral disc degeneration.