静水压对人体腰椎间盘一氧化氮产生及蛋白多糖合成的影响

Effects of hydrostatic pressure on nitric oxide production and proteoglycan synt hesis in human lumbar discs

目的:椎间盘代谢受许多因素影响,探讨静水压对人体腰椎间盘的一氧化氮产生及蛋白多糖合成的影响。方法:1998-05/2000-03在日本国富山医科药科大学骨科收集后方腰椎椎间盘摘除术所获标本69例样,样品切成1.0～2.0mm碎块后,3与1mL不含碳酸氢钠培养基DMEM一同装入2.5mL塑料注射器中,再放入37℃充满蒸馏水的能够培养椎间盘组织的装置,分别提供0.1,0.3,3MPa气压。蛋白多糖合成由35S-硫酸盐结合率来测定。无活性、稳定的一氧化氮的最终产物亚硝酸盐浓度用分光光度法测定。结果:0.3MPa蛋白多糖合成最高,约为0.1MPa的1.3倍;3MPa抑制蛋白多糖合成率。但静水压对一氧化氮的产生起着逆转效应。在0.3MPa一氧化氮的产生量和0.1MPa的相比略微降低,而3MPa增加一氧化氮的产生量,约是0.1MPa的1.34倍。结论:人的突出腰椎间盘组织诱导一氧化氮产生,其一氧化氮产生和蛋白多糖合成的改变与静水压有明显的相关性。高负荷静水压(3MPa)增加一氧化氮产生量而减少蛋白多糖合成。需要进一步研究澄清在人体腰椎间盘静水压环境下基质金属蛋白酶产生中一氧化氮发挥的作用。如果在椎间盘代谢中一氧化氮的作用得到明了,提示可用特异性抑制诱导型一氧化氮合成酶或一氧化氮的药物阻止或延缓腰椎间盘的退变过程。

AIM: Intervertebral disc metabolism is influenced by multiple factors. To inve stigate the effects of hydrostatic pressure on nitric oxide(NO) production and p roteoglycan synthesis in human lumbar discs. METHODS: From May 1998 to March 2000, 69 lumbar intervertebral disc specimens were collected from patients who had undergone posterior discectomy in Departmen t of Orthopaedic Surgery, Faculty of Medicine, Toyama Medical and Pharmaceutical University, Toyama, Japan. The specimens were chopped into 1.0 to 2.0 mm3 small cubes, and then the cubes were incubated in a plastic syringe(2.5 mL) with 1 mL Dulbecco's Modified Eagle's Medium(DMEM).The syringes were placed in an apparat us filled with distilled water that could culture lumber intervertebral disc at 37 ℃. Hydrostatic pressures of 0.1, 0.3 and 3 MPa were provided respectively. T he proteoglycan synthesis was determined from the rate of 35S sulfate incorpora tion.Nitrite(the non active and stable oxidation products of NO) concentrations in DMEM were determined by a spectrophotometric method. RESULTS: The rate of proteoglycan synthesis was the highest when exposed to hy drostatic pressure of 0.3 MPa and was approximately 1.3 times of that at 0.1 MPa , while 3 MPa pressure inhibited the rate of proteoglycan synthesis. However, th e hydrostatic pressure had inverse effect on NO production. At 0.3 MPa, NO produ ction was slightly decreased, as compared with that at 0.1 MPa, whereas at 3 MPa ,NO production was increased and was approximately 1.34 times of that at 0.1 MPa . CONCLUSION: Human herniated lumbar intervertebral discs spontaneously produce NO. There is a clear correlation of hydrostatic pressure with induced alteration s in NO production and proteoglycan synthesis. High hydrostatic pressure(3 MPa) increases NO production and reduces proteoglycan synthesis. Further research is required to clarify the role of NO on the production of MMP in response to hydro static pressure in human lumbar intervertebral discs. If the role of NO in inter vertebral disc metabolism is clarified, the specific agents that can inhibit the production of inducible nitric oxide synthase and NO can be used to inhibit or postpone intervertebral disc degeneration.